I was seriously just about to ask the same question; I’m glad I checked first!
I agree completely with itmustbeken; it seems like using a paper towel (or if you have one of those microfiber cloths) dampened with warm water is perfect for the aluminum finish and screen. I haven’t tried it on the plastic parts, but there’s no reason it shouldn’t work.
This actually works surprisingly better than anything else I’ve seen for the screen. Save for a stray fiber or two, it leaves the display looking as if it was brand new. (side note: I have the matte-finish MBP, so I’m not sure how well this works on glossy displays—does anybody know?).
sweet avatar btw