E.g. I told it to generate an address with "gavin" in it, and it chugged away for an hour or two and came up with:
12kUimDnb1a6oAPifgavinAaxMmLe43UR6
This is recommended for fun and experimentation only; it takes a long time, and while it is trying to find an address with the right string in it no other RPC commands are accepted. Including 'stop'.
It'd be kinda cool (and would speed it up a lot) to make it case-insensitive. Or to match to an arbitrary regular expression. Or to make it spin off a separate thread and just return "working...." (and have the thread add the address to the wallet when it is finally found, labeled with the vanity string).
Maybe we should have a Best Bitcoin Address contest
