Brown University's Lineogrammer

There are so many interesting pen-related ideas in the above video, I'm just baffled. The alignment tool near the end seems very nice.

They kind of gloss over their very interesting GestureBar. A common criticism to gesture interfaces is that gestures are hard to discover and remember. I think GestureBar improves the approachability of their gesture-based interface in an elegant way.

More about GestureBar below.