Here is a mini-tutorial for the "skin" mod in Portal to make Chell dressed in camo. first download this www.fpsbanana.com/skins/53296. then go to computer in the start menu, and go to C:\Program Files\steam\steamapps\(username)\portal\portal. when you get the rar. file downloaded you should see a folder called Materials drag this onto the 2nd portal folder and start up the game! To remove drag the Materials folder to the desktop.