Nolan Bailey is a pseudonym for John Romero. Yes, that was The Romero. I'm really John Romero. And no, you can't touch my hair, dammit. Everyone knows my hair is way better than Romero's.
Optical mice are all right, but they require a flat, stable area.
You can't get food anywhere near the pad, and if you get fingerprints on the pad, forget it. But I like the Keytronics mouse that doesn't use a ball. Instead it uses two wheels to make direct contact with whatever surface the mouse is on. The wheels are connected directly to the optical trackers. Use PS2rate to kick up the sample rate, and you get some great tracking.