Cool, I have a 3 DE0-Nanos and was running them at 6.67 MHash a sec, powered by USB. I thought it would be cool to try to build something with the largest non-bga FPGAs from Altera but I guess it would be far from profitable at this point.
I've got mine up to 35Mhash/sec, albeit with a custom power supply hack (bypassing the onboard regulators and directly supplying 1.2Volts at around 2 amps). Even if you keep the USB connection for comms you can supply 5V externally at around an amp or so (if you blow a lot of air over the regulators) and push it up to around 15-20MHash/sec.
BGA packaging is a huge problem for the hobbyist. I managed OK with the 144 pin TQFP's (using a commercial breakout board), but it really limits you to the very smallest devices. I completely balked at BGA (I picked up a Xilinx LX9 in BGA really cheaply, just to see what it looked like, but I haven't even tried to mount it on a PCB, its just not going to work with what I can produce at home). I'm currently waiting for bitcoin difficulty to explode sufficiently to pick up some LX150 boards cheaply to play with for my Litecoin project, though the ISE license will be a problem (only 30 days evaluation, and a full license costs an arm and a leg). If anyone's got a Ztex LX75 board going cheap I'd be interested to hear from you
