This video from Microsoft shows off a prototype device that projects a screen onto a tabletop and then allows you to interact with it via motion sensing. Probably the best example of it's use in the video is they have one side of a chess board (the side you are playing) as physical objects and the other side as virtual. So the person you are playing against is displayed via the projection over the chess board.
This video features the table top (projection from above) display combined with a touch and voice recognition interface for Warcraft III and Google Earth. First they show Google Earth and the guy uses his hands to pan around, zoom in, select regions, and measure distances. He also combines in some voice commands which compliment the interactivity provided by the touch display. Next up he demonstrates using the screen to play Warcraft III. He selects a group of units by placing an arm on each side of the units and he also uses voice commands such as 'build farm' which pops up a farm to be built by the next available worker and then touchs the screen to show where it should be built. At the very end they show a quick clip of two people controling the same Warcraft III interface.
Here is a pretty funny video which is sort of a spoof on all of the California cow cheese commercials. There is a ninja guy out walking in a field and he meets up with a cow. The cow turns all even on him and attacks him ninja style. For the most part the cow beats the crap out of the ninja guy with various ninja cow moves combined with Matrix special effects such as slow motion. About four 6ths of the way through the ninja guy figures out the cows secret which is it's udders. He starts attacking the cows udders and finally drains the cow via it's udders. One inconsistancy was I thought only bulls had horns but this cow has horns AND udders. Spending a little to much time near your local nuclear power plant eh?