LooToGo is a Google Map that shows the locations of public toilets in Germany. The site currently has over 28,000 restrooms in its database.
It is possible to search the map by location. If you click on a map marker you will be taken to the reviews section for that public toilet. If you know of a loo that is missing you can even add it to the map.
LooToGo also comes with an iPhone app, so now you can find your nearest toilet when you are out and about and caught on the hop.