Over on the Wired How-to Wiki, they have a nice step-by-step write up on making your own kegerator.
Even a low-end commercial kegerator will run you $400 or more, and a nice one will be more than $600. If you’ve got a spare fridge, you can build a kegerator for around $200. It’s easy to do, and well worth it. We should know: This how-to is based on Wired’s own kegerator construction project.
They even have a video which I’ve embedded here.
Some day I’ll have a kegerator for my homebrew. Kegging is so much easier than bottling.