I love the idea of a driptray. We didn't add one to our ghetto kegerator, because it's used outside but adding one would certainly be less messy. Another thing to think about is trying to insulate it somehow. Even on not-hot days, the ice melts so fast that some insulation would be great.
I totally stole Biermuncher's write up in BYO, and lschiavo and I built this: (we have joint custody)