G4tv.com fired up Portal on the Xbox 360 version of Orange Box and learned the ins and outs of the game.
This is a spoiler-free hands on.
"It really is a new way of thinking about puzzle solving. Some of the later puzzles require a lot of planning and quick shooting to open up new portals. You get a real sense of accomplishment when you finally figure out how to manipulate the portals and physics to solve a puzzle."