The recent commercials for The Orange Box piqued my curiosity, especially the Portal portion of the game. The wormhole gun concept seemed like an interesting variation in the First Person Shooter game line. The commercial has worked so far: I went to their website, was impressed by the game trailer and am now considering buying the game. The infinite variety of being able to transport from any wall, floor, or surface to any other boggles the mind.
Then again, there is a flash version of this concept. I might just stick with that.