With Portal 2 knocking Team Fortress 2 from the limelight this week, many people are probably wondering what the hell they're going to do with all those hats they've picked up. Well, you can use them in Portal 2.

Six of the most iconic Team Fortress 2 hats - and really, hats is what that game is all about these days - can be equipped and used by Portal 2's co-operative mode robots. You have to own them already in Team Fortress 2, of course.

Those hats are the Mann Co. Cap, Prince Tavish's Crown, Pyro's Beanie, Fancy Fedora, Master's Yellow Belt and Tyrant's Helm.