Wow. I mean, I knew Portal and Half-Life 2 were running off of the same engine, but I didn't think it would take only a week before somebody smashed them together. Take a look at Half-Life 2, as played with the portal gun. This sounds like the best first-person shooter ever, except for the fact that it's probably incredibly easy to play and you could probably break the game in seconds using this hack. Talk about a QA nightmare.

Still, though: incredibly cool. And even better, the hackers provide you all the info you need to do it yourself.

Half-Life 2 Portal [Primotech]