Please don't talk down to people like that, it's not constructive, and given the nature of a lot of the conversations on this board, I don't think this was an invalid question.

Answers:

Yes. Yes.  : https://en.bitcoin.it/wiki/Weaknesses#Attacker_has_a_lot_of_computing_power

No.  I'm not sure what would happen.  If you have a good idea, and think that the consequences make it not something to worry about, I think many people would like to know that information.  That's pretty much why I asked.  Should we be concerned?  It sounds like no, but you haven't really explained why.

Here are my conjectures:

It seems like the double spend is probably not practically useful, since it's less of a double spend and more of a "spend and then unspend", which only helps if you're getting something from someone else for spending the bitcoin.  And in that case, the other party would start squawking up a storm about it, so it  wouldn't go unnoticed.

Forcing transactions not to be confirmed seems like it might be something to be concerned about.  It could be hard to determine why its happening, and could be used as a weapon against people that piss off the pool.  Of course, that requires the pool to know which transactions belong to that person, which is sorta the whole point of anonymity in the blockchain.... but I'm not sure how hard it would be in practice.

Preventing other miners from getting blocks seems like the most likely attack vector, since it could be the hardest to recognize.  The top two pools could just give themselves 10% more block awards by rejecting 10% of blocks submitted from outside their pools, and waiting until one of them finds the block.  I'm not sure how obvious that would be to people watching transactions on the block chain.  The benefits are obvious - they get 10% more block awards than they're entitled to.

I'm relatively new to bitcoin, so some or all of this may be off, feel free to tell me where I've gone wrong, after all, I am trying to learn.

Should we be concerned that over 50% of the mining power is controlled by two pools? https://blockchain.info/pools

This seems like a really bad concentration of power for a network that is supposed to be decentralized.  Sure, it's handy when you need to fix a bug in the system, but it's also a weak point that can be exploited.  Thoughts?

So, I'm not an expert on bitcoin, but I've been writing software professionally for 14 years... and if you're planning on making a website that handles peoples money, you need to be rock solid with your dev skills.  You sound sound like you're having some difficulty with some of the basics, so maybe start with something a little less ambitious?  I'm really not trying to be mean, just trying to be helpful and realistic.

The way I would imagine most gambling websites work is, you deposit coins into one of their addresses.  After they are confirmed (no website should let you use coins before they're confirmed), they record your tally in a row in the DB.  From this point on, your "balance" is entirely virtual and has no relation to any real wallet.  Wins and losses are recorded in the database (likely there's a transaction log so they have accountability if someone says their account is wrong), and they update a boring old account_balance for you.  You don't need to calculate the value based off the transaction log, that's processor and database-heavy and unless you have a bug, should never be different than the constantly-updated balance.

You have to be really really careful not to let people spend more than they have.... it'll almost certainly be a common occurrence that people will bet down to their last satoshi, and might be participating in multiple games at the same time. You have to make sure that they can't bet .5btc on two different games at the same time if they only have .5btc left, you know?

Making a gambling website is a lot of work, you're dealing with someone's actual money, so you have to be super extra careful not to mess anything up.  I admire the spirit and ambition, but it's probably not something one person should try to write by themselves.

Another problem is that many of the wallets are multi-platform, and that means using cross platform gui tools like gtk or java... which generally look significantly crappier than native applications.  I think what is likely to happen is that the cross platform backends (like bitcoind) will get native OS frontends that look and behave like native applications (or even better). 

Also, right now, since almost all the wallets are open source and free, there's not a lot of economic pressure on developers to make their wallets pretty.

If you're not sure if you're being sexist, use this guide:

Replace woman/girl/chick/babe/blonde/etc with "black guy".... if your post now sounds racist, it was sexist to begin with.  If it now sounds gay, it was *definitely* sexist.

The reason there are fewer women in tech is because of sexism.  That carries over in to bitcoin as well, yes, but that's not a reason to repeat the mistake here.  Maybe the universal appeal of bitcoin is a way to try to include more women and build out from there.  Hell, if you want to be completely mercenary, having the other 50% of the population interested in bitcoin will just drive up the price.

They have directions on their site. Look for a link called levels and limits.  basically, you need to give them a credit card number and then wait 30 days after your first purchase with them.

I bought at 800 when it had stabilized there for a while late November (and was pretty happy when it went over 1100) and then bought at 725 as it was falling from 1000 after China closed up shop.  There was a little bump in the drop and that's where I bought, figuring it was going back up and a 25% drop was all that was likely to happen.  Well.... not exactly.  I wanted to buy more when it hit 500, but I'm not made of money, and my wife said we'd spent enough already, heh.

So, all prices are pretty much determined by the prices on the exchanges.. but why? What makes Mt Gox the determining factor for all Bitcoin dollar prices?  It seems like a self fulfilling prophecy, people expect to use Mt Gox as the value, so set their prices accordingly, even if they don't have any relation to the site. Is it just because those are the biggest markets? But are they? How would we know if another market was bigger?

Explain why?

Is there a desktop wallet client that uses two factor authentication?  I know it's an extra step of paranoid, but, well, that seems not entirely unjustified.  I googled, but to no avail... too hard to filter out the online wallets with 2FA.

...for some definition of pronounceable? 

If it's going to be that long and that bizarre, I don't think the trade-off of length vs. sorta pronouncability is worth making.

And as others said, any one particular address should not be something users bother themselves with.

So, let me back up a bit. I didn't mean to say that my suggestion was the only way, or even a particularly good way. Mostly, I just wanted to suggest that there needs to be a way to make it easier for nontechnical people to use addresses even if they sacrifice a little privacy. Obviously, sacrificing all privacy is not acceptable.  Maybe there's no middle ground in Bitcoin, if so, then so be it. I just didn't want it dismissed out of hand just because it's not ideal in all circumstances.

I just looked up bip32, that does sound like a good fix for when you want to let someone make repeated payments without then all going to the same address.

Mostly, I just wanted to hide the ugly complexity of Bitcoin addresses from casual users.  I'll take a look at the rest of the BIPs and see if any sound like they'd cover what I'm talking about.

Apologies for being one of those noobs that comes in offering changes without properly knowing what I'm talking about.  I should have phrased my question more carefully.  Something like "is there a way to hide the complexity and ugliness and inherent illegibility of Bitcoin addresses from casual users, such that one can easily give out a single human readable token that can be used for multiple transactions possibly from multiple people?"

Honestly, most people don't care about privacy. They just want something easy.  Making a new address for each transaction only works when the receiving party is an active participant in the transaction. This is often not true, such as a landlord getting paid by his tenants, or donations & tips.  Anonymity is there for people who want it, but many people would rather have some convenience instead. 

No one types addresses now because it's so hard  

Here's some use cases:

Billy calls home from college and asks mom for money and wants to give her his address
The Red Cross has a tv/radio ad and wants to give a donation address

Basically any time you need to communicate an address through a medium that doesn't have copy nad paste (phone, TV, radio, billboards, in person)

Also useful because when you go back to look at your history you can tell who the money went to.

It seems like, one barrier to adoption for the mass market is how ugly and non-memorable addresses are. I know that on the back end they need to represent people's public keys, but it seems like it should be easy enough to hide that from the end user.  If the clients simply signed a document that said "this address may be aliased by this name", you could then have clients able to send money to the name not the address. You then have the clients verify that no one else has signed a document with that name to keep it unique. To support one name across multiple addresses, you can have that first address sign for other addresses, which could then sign for other addresses, etc.

That way, you could send money to something human readable rather than an unintelligible string of characters that is easily typoed or even maliciously altered.

Thoughts?

This thread has a fork of bamt for litecoin mining, with a version labelled 1.2, FWIW: https://litecointalk.org/index.php?topic=2924.0  (and download links for anyone who wants to get bamt).

High 5 figures is honestly laughable.  You need an ops guy, at least a couple devs, and at least one legal guy.  You can't get any of those guys for less than 80k a year, and spending 100k will get you much better candidates (and therefore much more likely to actually succeed).  Those guys need benefits, or they're going to go somewhere else, so that's another 40k each.  You're looking at over 500k in the first year just for salaries of the core employees.... and yes, again, you want salaried people, not contractors or freelancers.  Contractors don't magically produce maintenance-free code.  You'll have bugs and new features and all that... there's never a time when developers are short on work, so you might as well have people who are invested in making the company succeed.

Software development is expensive.  Really really expensive.

The idea is simple, the execution never is.

PI said this on another guy's post, and I'll say it here. This is people's *money* you're dealing with. You can't just throw some code up and hope there aren't any bugs.  If a chat bot had a bug, someone disconnects or a message is lost/garbled. If an exchange has a bug, a lot of people could lose a lot of money.

I have a software degree, too. And 14 years experience, half of that at a company that makes financial software.  You might be able to make something that kinda works, but I guarantee you that th err will be bugs that cost people money.