· Microsoft Blackboard: A physics puzzle that lets you use gestures to build a virtual machine of gears, fans, and seesaws.

· Microsoft Garden Pond: Gently move your origami creations in a virtual pond.

· Microsoft Rebound: A game where you "propel a ball and annihilate your opponent" on an electrified court.

· Microsoft Surface Lagoon: A screensaver where you use multi-touch to interact with the fish.

Will multi-touch someday make the keyboard and mouse obsolete? Not in the near future, certainly. But it's bound to play an increasingly important role in human-computer interaction.