Haha, aside from the obvious problems of storing 2^256 hashes somewhere, having a database system that can handle all of the btc client connections, and undermi

Haha, aside from the obvious problems of storing 2^256 hashes somewhere, having a database system that can handle all of the btc client connections, and undermining the actual proof of work system behind bitcoin's credibility, you'd be creating a useless rainbow table that didn't have any common cleartext passwords hashed in it.