I'm really too busy to build this myself, so I need developers. Obviously this is pro bono work, no pay, but the karma's fantastic. If you're interested, e-mail me at email@example.com, and please use "Help Wanted: Rails Volunteer Work" as the subject line, because I'm already behind on my e-mail, and anything which makes it easier to organize makes it easier to do.
Update: I got way more responses than I expected, so I'm not sure what to do now, but on the upside, there's now a
#radogchannel on freenode (stands for Ruby Automated Donation Generator, I think).