in all honesty though, the best thing to do is go out and by those giant rolls of plastic sheeting and cover your floors with it. first campus party me and my buddies threw a few years back was a multi-kegger (a free one too, courtesy of my new accepted med-school roommate) and it was the best idea we've ever had. the place got completely trashed and was full of mud and dirt and beer, and all we did was peel the sheeting off the next day, ball it up, and throw it out. if you do a good job -- we measured it, cut it precisely to fit around corners, and taped it down -- it'll prevent a hell of a lot of clean up.
now of course im suggesting that based on the assumption that you don't have carpetting, because if you do, you pretty well lose. shits gonna get stained and destroyed in a hurry.