Ask "yes or no" questions until the identity is guessed, and then the person who guesses correctly takles on an identity and the guessing game begins again (if you're still unclear, look to the title for guidance on how to play this.)
Now, are you ready? (If I said "You Bet Your Life I am!" that'd be too easy to start, huh? OK, I'm thinking of a person...OK, I'm from a play...) ;)