Cases for Multiple Single Board Computers?

dewboy asks: "We're trying to set up a rack of SBC's (Single Board Computers) that will allow us to plug a certain number of SBC's into a backplane which will provide power. All interfaces (mouse, keyboard, VGA, Enet, etc) are on the faceplates of the cards, so all they really need is power. All we've been able to find so far are chasses that support a single SBC and a (4-20 slot) backplane. What we'd like is a chassis that supports 20 SBC's. Has anyone found anything like this?"