http://www.visionarium.us/htm7/visionarium.html

Have a look at these. I don't know of anyone who has used them and I'm not sure how well they would ventilate through the corners, but they look great and are stackable. You can even buy dividers to help save some more space and money.
If anyone here has used them, I'd like to hear what you think about them as I have thought about getting a couple myself.