If you have a phone like the Galaxy S and you don't like its smooth, almost cheap-looking battery cover, XDA-Developers forum member mhaedo shows us how he got his Nexus S looking smooth, matte and fingerprint-free.
The only thing you need for this mod is an inexpensive can of Plasti Dip, a spray-on plastic product that will greatly improve the appearance of your phone. It will give you a better grip, keep it from looking cheap, and (as an added bonus) stop it from being a fingerprint magnet — no sandpaper required. What's especially nice is that, while it won't peel off easily on its own, you can peel it off any time you want to go back to the original look or try another case. Hit the link for the full instructions and for more photos.