A new technology coming out of Microsoft Research called InkSeine. InkSeine is basically a future tablet PC application that allows richer interaction with the web and desktop applications and your tablet PC. Gestures - things like Pen Flicks are one of the main ways that InkSeine works, from the video it seems like a very natural way of working with a tablet. The way you can search direct from a highlighted inking is particularly cool, picking where you want the search to take place, for instance, the web or documents.
Check out the cool video of InkSeine in action! (.WMV)