Very cool. For more fun shared drawing, I also love Aggie.io. Entirely HTML5 and JS, yet fairly powerful and exports to PSD.
I only wish it supported pen pressure on Linux.
Pretty neat since this works with Linux! I might have to try this out and see if it can replace Autodesk's sketchbook (which just became free for personal use recently)
This thing is neat because of the networking functionality, but I'd definitely say Krita is the better FOSS painting tool on Linux.
What is this built on? I had a quick look at the source without luck!