The couple times I have misplaced my phone, I always call it right away using someone else's phone. Both times, no one had picked it up yet and I heard it ringing, but I would hope that if someone had, they would answer the phone and I could get it back that way.I dont bother with a lock. All the info is on the memory stick anyway, which is easily read on any pc. Also, if I do lose it, the finder could not call anyone to let them know it was found.
I have found a few phones, and always called the most recent# and told them to get a hold of the owner.
I have to lock my phone because I pocket dial people if I don't. It is usually my dad, who lives in CA - 3 hours earlier than me. He doesn't like getting calls at 4 am (it has happened several times and he always answers because he is the person I would call if something happened to his parents or my kids).