So how did that work? 'Any muslims here before we get started?' 'Oh, me! Me!' 'OK, lessee ya prove it.' Do muslims have a tattoo or something?
For males, circumcision is a very reliable method outside the US and Israel.
You can always tell a mohammedan. Every other sentence is said in a high-pitched voice, and ends with "I svere to God, we peace-loving."