Valve's got a new game in the works, and it's quite the mind-bender. Portal is a puzzle/FPS hybrid that will utilize holes in space to do the impossible
. From the Ars Technica post: "That video makes my brain hurt in all the right ways. The set up and voice-over are both hilarious, and at first it seemed rudimentary to me. Then everything goes crazy and you start to realize just how much you can do with this technology. I'm looking forward to seeing fan-made videos hit the 'Net with all the insane stunts and tricks you can pull off. This seems to be one of those games that you'll have as much fun playing with the game as you do simply playing through it."
This is a title definitely worth checking out for yourself