Ziteboard - Ziteboard is an zoomable online whiteboard that lets team to collaborate in real-time.
Tworlds - Swap photos with strangers around the world, anonymously
Voynetch - Share your visual notes and graphic recordings.
Just a Minute - A web experiment to see how well you can estimate a minute.
AuthorBee - Organize Twitter around your interests
The Evolution of Trust - an interactive guide to the game theory of why & how we trust each other