Try using the new experimental html5 version as currently drawing onto the online canvas uses flash 10. But not for long!

Welcome to Drawsum, the free wiki-style collaborative art project.

To cut a long story short, Drawsum does for art what Wikipedia does for encyclopedias: make them free, open, changeable and collaborative. Drawsum is one massive shared canvas, where anyone can draw anything and let their creativity run free! So you can add your drawings to the ever-changing online canvas and see it evolve.