Wikipedia - the mother of all online, collaborative projects (MySpace notwithstanding). With the speed at which intellectual capital is developing and being shared, it's about the only way I can keep up with getting an understanding of new terms and concepts. It is built on top of a Web 2.0 technology, using open source Wiki's. The world participates - I even wrote some of the content....
When there, search Project Based Learning and look for "21st Century Project Based Learning - iPBL".
