Sure, you can buy a kegerator, but why would you when you can build one? Geek bible Wired Magazinehas published a really good guide on how to do it. Step-by-step instructions can be found here.
(Bonus: The instructions are in a wiki, so if you’ve got some expertise in kegerator construction, you can add your own tips and tricks.)
And for those of you who find that whole reading thing too difficult, you can watch the video instead: