OOH! Turi, me and my friends did that 2 nights ago.

We were at WalMart, walking by a payphone when it rang. My friend answered it. When the person asked to speak with Susan, she gave the phone to me. So I started talking, playing along, and they asked for Steve. So I gave it back to my friend (Jocelyn).. She told the guy that she had a cold, which is why her voice was all wonky. Eventually they caught on and hung up though but it was fun while it lasted.