Apple has had a tough last few weeks, all things considered. Flocks of irritated customers have been complaining about a brown discoloration of the white iPhone 3G S casing, originally thought to be the consequence of overheating.
As it turns out, new reports suggest that the discoloration is actually a reaction due to contact with third-party iPhone cases. More importantly to you, the coloring can easily be removed by rubbing your iPhone down with alcohol (beer app probably won’t do the trick). I personally have the black iPhone so I can’t try this out myself, but if you do, let us know how it works out for you.