Got this link from my buddy Q! over at Valve Software. There’s a software development kit that you can download from them that allows you to create your own levels and whatnot using the Steam Engine. The guy who did this one re-enacted one of my all-time favorite movie scenes using Half-Live 2 characters. It’s the crux of the movie A Few Good Men where Tom Cruise hounds Jack Nicholson into admitting that he ordered the beating of a soldier. You know the one, the whole "You can’t handle the truth" scene where Jack chews up the scenery?
anyway, this was expertly done by Randall Glass, whose site you can visit here.