Ambient Design's ArtRage has won first-place and \$100K in a contest sponsored by Microsoft to boost the TabletPC. The product is a favorite among TabletPC users with any artistic ability at all (and thus, unfortunately, excluding me). I also think it's a pretty good way to boost the platform, a relatively cheap way to inject some cash into the smaller, entrepreneurial companies that are most likely to produce the killer apps for the Tablet.