I've never tried this, but I've heard this suggestion many times, so I'm seconding it.Use a magic eraser; it'll tear the eraser to shreds but the keyboard looks like new!
I do the same, but with a 50% isopropyl/50% water solution.I use a lightly damp paper towel regularly with no ill effects.
You gotta get one of these, a Moshi ClearGuard CS Keyboard Cover. You barely notice it and it fits perfectly. To clean the cover, soak in warm water in the bathroom sink with a little dishwasher detergent and just a little bleach. Ten minutes like new again.My keyboard is, unfortunately, used by other people and it is disgusting. Anyone have any advice on how I can clean it without damaging it?