My dorm has a bike room, but they racks are something you could probably set up yourself in your room. Ours are steel, but a couple of six foot 2*4's with rubber coated hanging hooks (hardware stores have them) should do fine. Set them up vertically (a little bit more lumber) about a foot apart with one hook 6-12" higher than other. Hang the bike on the high hook by the front wheel and the other by the rear. Takes up no more than 6 sq ft. Just be careful of spokes when pulling one out.

Of course, I don't see how a dorm could not have some sort of miscellaneous storage room you could arrange to lock your bike in.

Or be creative. The guy who designed our racks got a patent for them!