Ok, it's not absolutely new, but maybe WLTC would like to feature it in the Daily Plugins?
The Donations Cloud plugin by Zirona allows visitors to donate and leave a link with a link text. As soon as a donation is done, the blog is notified by PayPal, and the links will automatically appear on the receiver's website (at a designated position).
The cool part is that the donations appear as a cloud, similar to a tag cloud -- the size of the link is relative to the donation amount.
As every donor receives a link on your site, the motivation to donate rises significantly. (See my own donations cloud! ;))