My concern was existing solo miners.
I have always had bitcoind running and I was mining with these options:
cgminer -o http://127.0.0.1:8332 -u bitcoinrpc -p $PASSWORD

cgminer was displaying this:
Connected to 127.0.0.1 diff 4.25G without LP as user bitcoinrpc

Given that the difficulty matched the network difficulty I always assumed it was solo mining, was it not? How was I not mining "in a meaningful way" ? =)
Also I always assumed that cgminer would ask bitcoind for an address for the mined btc, in a similar way in which it asks for the difficulty.
The fact that it could have been sending the mined btc to some hard-coded address belonging to you really didn't cross my mind, and I still think it's a bit strange as a default. =/
So that's why when I read the 4.2.0 release notes I thought that this was a change in behaviour.
Were versions of cgminer previous to 4.2.0 already using your hard-coded address if one didn't specify --btc-address ?

Wouldn't it be possible to have the receiving address always displayed by cgminer while running? That would avoid any confusion, and would be quite an important piece of information to have. =)

Thanks for the release.
However, I don't think it's the right thing to do to make solo miners mine by default to an address owned by you, unless they pay attention to the documentation and add the --btc-address option.
Some people like me mine solo even if they have a low hashing power. They do so because pool mining wouldn't provide a significant income, and they rather take their chance with the solo mining lottery. You shouldn't assume that somebody doing solo mining has millions worth of equipment so if they don't pay attention to your documentation it's only fair to punish them by ripping them off of their mining.
In any case, simply upgrading a piece of software shouldn't require the user to add an option in order to keep the previous behaviour. And in this case the change in behaviour is quite dramatic: all mining will go to your address instead of the one belonging to the user!
This is a bad default because it is most likely not what a user would want to do by default, and the most sensible default behaviour should be for cgminer to refuse to start and print an error.
The problem here is that obviously there are money involved, and I think this really reflects negatively on your reputation and the reputation of cgminer.
The fact that a piece of software is given away for free doesn't mean that the developer doesn't have to behave professionally and treat his users with respect.
Other high profile open source software like Linux or Apache certainly would never do anything like that.

I had the same problem.
I first considered bullionbypost.co.uk as it is running a lot of ads on both tv and the internet. It seems like a big company until I realized that its price were quite high.
I then looked at ukbullion.com. It seems like quite a big and reputable company and its prices are noticeably lower than bullionbypost so I just went for it. So far I bought 1 gold and 1 silver bullions and everything went fine.
Regarding the VAT on silver I don't think there is an easy way to avoid it. You can buy VAT free silver from Guernsey which is an island in the English Channel and then take it to UK, but that would be a bit of a risky operation as it effectively would be smuggling and it would be illegal.

Mining solo is a perfectly valid choice which is quite underrated. I'm mining solo with my 6 usb erupter simply because I don't care about the small profit I would make with pool mining.
So I rather take my chances with solo mining. The biggest share I found so far is only 8.5M but I don't loose my hope, and it's fun to check every morning if there is a "surprise".
Obviously I'm also still fully contributing to the bitcoin network, whether I will mine a block or not.

A big +1 to add support for btcchina. Just have a look at bitcoinwatch.com and see the volumes, from what I can see btcchina is about to take the number one spot. It's just a whisker from mt
gox.

You can use it as an electric heater to warm up your house during the winter.
Its 620W power usage happens to be a good value for that purpose. Unlike BFL asics that with their 100W wouldn't be that good at that.
And you will still have the nice feeling of being contributing to the bitcoin hashing network.
Another advice: when the difficulty will get so high that you will no longer care about the income, switch to solo mining. At least you will still have a chance albeit slim of paying off your investment.
I switched to solo mining with my 335MH usb miner precisely for this reason.

One good thing about this miner?
According to http://www.bitcoinx.com/profit/ with 2.5W power consumption and with BTC around $100 it will be able to pay for its electricity and be profitable until difficulty will be around 1,950,000,000.
That's kind of cool isn't it?

I finally managed to get cgminer 3.2.1 to work with Debian 7.0 ! 

Her's what I did:
sudo cp cgminer-3.2.1/01-cgminer.rules /etc/udev/rules.d/
sudo service udev restart

Now unplug and plug again the usb erupter.
Restart cgminer and it should work.

cgminer 3.2.1 no longer requires to specify the serial device, nor any icarus timing options. I also read that it should improve the hashing rate compared to 3.1.1.

I finally managed to get cgminer 3.2.1 to work with Debian 7.0 ! 

Her's what I did:
sudo cp cgminer-3.2.1/01-cgminer.rules /etc/udev/rules.d/
sudo service udev restart

Now unplug and plug again the usb erupter.
Restart cgminer and it should work.

cgminer 3.2.1 no longer requires to specify the serial device, nor any icarus timing options. I also read that it should improve the hashing rate compared to 3.1.1.

The nounce is the number that has to be added to the rest of the data in order to obtain a hash that satisfies the difficulty by being smaller than a certain value.
So what happens is that a mining device would report that the hash of a given nounce+data satisfies the difficulty when in fact it doesn't because the computed hash is wrong due to an hw error.
So I think what is bad is the hash computed by the miner. This in turn would cause the nounce being tried "bad" (generating a hash that does not satisfy the difficulty).
Somebody correct me if I'm wrong.
I think it's just a matter of how the error message has been phrased.

That fixed it thanks! 

How to fix it with Debian 7.0:
sudo cp cgminer-3.2.1/01-cgminer.rules /etc/udev/rules.d/
sudo service udev restart

Now unplug and plug again the usb erupter.
Restart cgminer and it should work.

I have a problem with cgminer on my AsicMiner usb erupter.
3.1.1 works fine, but 3.2.1 gives me this never ending series of errors:

[2013-06-08 19:38:12] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
[2013-06-08 19:38:12] Icarus detect (1:9) failed to initialise (incorrect device?)
 [2013-06-08 19:38:17] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
 [2013-06-08 19:38:17] Icarus detect (1:9) failed to initialise (incorrect device?)
 [2013-06-08 19:38:22] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
 [2013-06-08 19:38:22] Icarus detect (1:9) failed to initialise (incorrect device?)
.....

The only usb connected mining hardware is the AsicMiner usb Erupter.
I set the same permissions on both 3.1.1 and 3.2.1:

-rwxr-sr-x 1 andrea dialout  304853 May 24 09:46 cgminer-3.1.1/cgminer
-rwxr-sr-x 1 andrea dialout 1160140 Jun  8 19:35 cgminer-3.2.1/cgminer

Running debian 7.0.

cgminer compiled with ./configure --enable-icarus --enable-bflsc --disable-opencl

------------------------------------------------------------------------
cgminer 3.2.1
------------------------------------------------------------------------


Configuration Options Summary:

  curses.TUI...........: FOUND: -lncurses
  OpenCL...............: Detection overrided. GPU mining support DISABLED
  scrypt...............: Disabled (needs OpenCL)
  ADL..................: SDK NOT found, GPU monitoring support DISABLED

  Avalon.ASICs.........: Disabled
  BFL.ASICs............: Enabled
  BitForce.FPGAs.......: Disabled
  Icarus.FPGAs.........: Enabled
  ModMiner.FPGAs.......: Disabled
  Ztex.FPGAs...........: Disabled

Compilation............: make (or gmake)
  CPPFLAGS.............:
  CFLAGS...............: -g -O2 -I/usr/include/libusb-1.0  
  LDFLAGS..............:  -lpthread
  LDADD................:  -lcurl   -ljansson -lpthread     -lm -lusb-1.0  

Installation...........: make install (as root if needed, with 'su' or 'sudo')
  prefix...............: /usr/local

I have a problem with cgminer on my usb erupter.
3.1.1 works fine, but 3.2.1 gives me this never ending series of errors:

[2013-06-08 19:38:12] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
[2013-06-08 19:38:12] Icarus detect (1:9) failed to initialise (incorrect device?)
 [2013-06-08 19:38:17] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
 [2013-06-08 19:38:17] Icarus detect (1:9) failed to initialise (incorrect device?)
 [2013-06-08 19:38:22] USB init open device failed, err -3, you dont have priviledge to access - AMU device 1:9
 [2013-06-08 19:38:22] Icarus detect (1:9) failed to initialise (incorrect device?)
.....

The only usb connected mining hardware is the AsicMiner usb Erupter.
I set the same permissions on both 3.1.1 and 3.2.1:

-rwxr-sr-x 1 andrea dialout  304853 May 24 09:46 cgminer-3.1.1/cgminer
-rwxr-sr-x 1 andrea dialout 1160140 Jun  8 19:35 cgminer-3.2.1/cgminer

Running debian 7.0.

cgminer compiled with ./configure --enable-icarus --enable-bflsc --disable-opencl

------------------------------------------------------------------------
cgminer 3.2.1
------------------------------------------------------------------------


Configuration Options Summary:

  curses.TUI...........: FOUND: -lncurses
  OpenCL...............: Detection overrided. GPU mining support DISABLED
  scrypt...............: Disabled (needs OpenCL)
  ADL..................: SDK NOT found, GPU monitoring support DISABLED

  Avalon.ASICs.........: Disabled
  BFL.ASICs............: Enabled
  BitForce.FPGAs.......: Disabled
  Icarus.FPGAs.........: Enabled
  ModMiner.FPGAs.......: Disabled
  Ztex.FPGAs...........: Disabled

Compilation............: make (or gmake)
  CPPFLAGS.............:
  CFLAGS...............: -g -O2 -I/usr/include/libusb-1.0  
  LDFLAGS..............:  -lpthread
  LDADD................:  -lcurl   -ljansson -lpthread     -lm -lusb-1.0  

Installation...........: make install (as root if needed, with 'su' or 'sudo')
  prefix...............: /usr/local

I've been trying to use:
--icarus-timing short
instead of:
--icarus-timing 3.0=100

It seems to be giving me a little more speed: about 335 MH/s instead of 334 MH/s

These options are explained in the file FPGA-README in cgminer source code.
The "short" options basically finds the timing by calculating it and periodically adjusting it in the first hour it runs. You will see a message in the log about these adjustments every once in a while if you try it.
The "3.0=100" is probably a safe timing that works fine for every unit. The thing is that all sticks are not exactly the same and some units might be able to cope with a slightly better timing value.

Both front and back if I can.
For the moment I stuck 4 of this little square copper heat sinks on the back plate, but the thing is still too damn hot.
I'm planning to remove them and attach a spare i5 heat sink I have lying around, problem is the 2 screws on the back plate don't let me place it properly, but I'm thinking of a solution.
The i5 heat sink I have is about 10cm wide and looks like this: http://www.ayagroup.com/images/D/E41997-002_2.jpg
See what I mean? That should take care of it right ?? ;-) It's so big that should be all right even as a passive cooler with the fan off.
The chip closest to the led is the one marked with "BE100" and it's the hottest because it's the chip that does all the hashing work, as it was also mentioned in a another thread.
It will sure be nice to stick a heat sink on that chip, the problem is that it is so small that those copper heat sinks I have might not stick to it firmly. And if for some reason it detaches and touches other pins on the board it might short circuit and burn the whole thing, and I don't want to risk it. If I find a smaller heat sink I will do it though.

Yes, I didn't think about the 3600 BTC figure which really makes this thing quite pointless.
Your second argument makes a more general rally involving everybody not only miners on the lines of "everyone buy 1 BTC" probably also infeasible.
One rally that could still make sense would be "convince a friend to buy 1 BTC".

I'm thinking of getting some good copper heat sinks to cool it down and maybe reduce hardware errors.

Something like this:
http://www.ebay.co.uk/itm/New-8pcs-Copper-Heat-Sink-Heatsinks-Cooler-For-PC-Computer-DDR-DDR2-Memory-RAM-/150934744374?pt=UK_Computing_Memory_Chipset_Cooling&hash=item2324696d36

or this:
http://www.ebay.co.uk/itm/Copper-Heat-Sink-For-DDR-DDR2-DDR3-RAM-Memory-Cooler-/390512454152?pt=UK_Computing_Other_Computing_Networking&hash=item5aec5b2a08

I propose carrying out an experiment involving all miners that regularly sell BTC for USD.
The experiment will consist in not selling any BTC for local currencies on Monday 10 June 2013 by postponing to a later time, like for example the day after.
The purpose of the experiment is to evaluate the consequences on the USD/BTC exchange rate.
Please leave a comment if you are willing to participate.

Hey A+C if you want to mine with my miner during the weekend I don't mind, at least I will know it is not faulty. Send it on Monday though if you can

Mining solo should be quite easy even though I never tried it as I don't have enough hashing power.
What you should do is:
- add 2 lines with "rpcuser=myuser" and "rpcpassword=mypassword" entries to bitcoin.conf
- keep bitcoind always running as normal
- run your mining software (like cgminer or bfgminer) and specify the username and password same as the ones in bitcoin.conf, and the ip address of the computer running bitcoind as the host (127.0.0.1 if it's the same). The port should be 8332.

example:
cgminer -u username -p mypassword -o http://127.0.0.1:8332

That should be it. However do some research and ask somebody with experience to be sure I didn't miss anything.
According to my calculations with current difficulty you have 1 chance in 60 to mine a 25 btc block in the first month.
Having more than 1 stick will multiply your chances.