yeah dude, that's the best advice. Just go to an Optical store (eyeware store) and ask them for a microfibre towel (the ones they give you to clean your glasses when you buy them.
i have couple one in my house and one that travels with me. The blackbook gets oily fingerprints and just using the towel will solve it. like Mitthraw....
said it it's getting too difficult to get out just dampen it with some water, SQUEEZE ALL OF IT before cleaning the computer and that'll do the trick