Going Native - Applying for German Citizenship

Having been here a few years, paying perverse amounts of tax, i thought it would be nice to have a say in who runs this country. So I was thinking about applying for German citizenship (I'll get me coat).

I've heard that you have to take a German test and that you have to relinquish your British passport (which I obviously don't want to do). Does anyone know what the procedure is for getting German citizenship and do I really have to give up my British passport?

Last time I inquired they told me there was no way to keep both passports, and depending on how long you've lived here the costs can also be crazy.

Unfortunately, the fact of the matter is that there is no way to get German nationality without giving up your British passport - which is why, despite a German wife, I ain't done it.