Lifehacker has a nice tutorial on getting your greasy fingerprints off your notebook computer, especially the track pad.
The magic is something that is literally magic, the Mr. Clean Magic Eraser. It is intended as a household cleaner that, according to advertising, works wonders on baseboards, floors, switch plates, and walls — and now on your dirty laptop.
Using the Mr. Clean Magic Eraser is easy. Wet the eraser and squeeze out the water. Wipe the spots on your notebook with oily build up and then dry it off.
Once nice thing about this solution is cost and value. They are cheap and last a long time.
Here’s a short video demonstration of the tip from Lifehacker: