Donation Clouds are a (rather) new approach to monetizing your website: If you want to receive donations, make an event of it!
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 -- where the size of the link is relative to the donation amount! (Hence the name -- donations clouds look similar to tag clouds.)