Most of the ideas here only work with GPU mining approaches by the way, FPGAs and especially ASICs are only useful for 1 single purpose (mining) - but are far more efficient at that.
It would require some jury-rigging, but I would assume most FPGAs made for mining could also crack SHA256-hashed passwords.
I'm with RedEmerald; if Bitcoin falls apart, I'll be doing my best to crack the BOINC top 100.
At least for a while, my electricity is reasonable.
You must have serious skills to play Crysis 3 on multiple computers at once.
Or use your CPU for finding fun/cool personalized bitcoin addresses 