I got a similar rack to the one mentioned above at Target, called The Art of Storage Leaning 2 bike Rack. I have it in my outdoor shed, but you could put it inside, and don't need to mount it to the wall. I could not believe how it holds both of my bikes. The arms are adjustable so it's very easy to move the bikes around.
http://www.target.com/p/the-art-of-s...m=bike+storage