Feature request #1297: Implement "Pledgie"-style donations system

GitHub can automatically set up "Pledgie" campaigns to accept donations for projects hosted there, but it would be nice if I could integrate similar functionality here so that people could donate to open source projects without ever leaving the site.

The key requirements are:

• transparency: the total of all donations, as well as the amounts of all individual donations should be in public view
• credit: those who donate should have the option of making their contribution publicly known if they want

Not a very high priority project, seeing as people tend not to donate much to open source projects (just take a look at the list of campaigns here), but it's something I'd like to implement one day.

It doesn't just need be for open source projects; it could be used for any kind of "campaign" ("bounty" style open source funding, for example).