An Expensive Area Rug
Unless your kid manages to squeeze a vacuum and steam cleaner into his or her minuscule closet, it's a safe bet that any area rug will be ruined beyond repair by the end of the school year. Dirty shoes, spilled sodas and crumbs galore have that effect on carpet.
Do your wallet a favor and hit one of those cheap carpet sales on move-in day, or pick one up at a yard sale. Twenty bucks will net your kid a perfectly functional rug for a dorm room.
Another alternative is to outfit standing spaces (by the sink/mirror, bedside or desk) with individual carpet squares, which typically cost less than $5 per piece.
Whatever flooring option you choose, don't harbor any delusions about putting the rug to use in the future. Trust me, it will be disgusting with a capital D.