Okay, technically this is an Orange Box question, not a Steam question. Or maybe it'll work for anything using Source, I dunno. But sorry I put it here, it's just the Orange Box forum is inactive and it's not a question for a specific game.
Anyways, I saw a screenshot of someone running one of the Orange Box games (I'm assuming that all the Orange Box games could do this) windowed, but so that the window is as large as possible. I would love to figure out how to do this myself so I could multitask while waiting for TF2 to load without getting a small gameplay window. :D
Help, please? Sorry if thi is already mentioned somewhere, I couldn't find information on this.