Here's a new site I came upon. It's called Page Rank 10 The SEO Experiment. The idea is by linking to this site you can improve your Google Page Rank and increase your traffic at the same time. They are currently PR4 but there goal is to reach PR10 by getting as many people to link to them as possible. Every time you send a visitor to them. Your site gets listed on the front page. Also as the PR of there site increase so does the value to your site. Sounds interesting. Have a look.