Lost and Found

Suppose a friend comes to you and says, "Hey, I'm looking for my friend, John. Have you seen him?" If you know at least a little about John, continue. Act as if you're confused. "John? Who's John? Oh! That guy with dark glasses! That tall and fair guy! The one who always hangs around with Nick, and owns a Yamaha bike?..... No, I haven't seen him."

It works better if the question wasn't asked to you, and you interrupted.