No idea? I'm not sure how it's done on other site, wether it's manual or automatic but I have seen a few site with a hosting donations section with a Target and current amount, but like I said it's probably updated manually rather than automagically.
It would be cool if we could though, then we could see where we stand all year round and not have to scrabble around at the end of the 12months. Although I bet no one would chip in till the last minute then either :P
Can do that easily and automatically if we went through a payment service provider, but obviously they would take a fee.
Might be viable if anyone has a fixed monthly fee one, that we could piggy back on, though I suspect they'll generally be charged per transaction.