My rig:
http://imageshack.com/scaled/large/853/fy7e.jpg10 block erupter's running 3.3G/H
ATX power supply
Raspberry Pi
I have three hubs as it was the only configuration I could find that was stable, I suspect the power traces on the hubs were not up to the job.
Waiting for my BFL 7G/H, and waiting to see whats next in ASIC before I spend any more $$
Phil