and some keys don't work anymore afterwards, don't bother trying to clean it :) You can take the keyboard apart to a great extend (see this guide for some info) and even put it back together so that it still works. But you can't get to the actual conducting paths which got dirty during the accident, as they are sealed between two plastic sheets. The coffee must have gotten there through some capillary attraction
 One learns something new every day.

Anyway, ordered a new keyboard (which by the way not every mac shop in town is willing to give you) and use an external keyboard until that on arrives :)