Re: Password protect it and you don't get it back.
I actually had a fun evening of hunt the owner a few months ago. I found the phone on a pub seat where two girls had been sitting. Me and my friends enjoyed our beers expecting the girls to return any minute. They didn't, so I rang the last number the owner had called, hoping it was the person they were with that evening. It wasn't, it was a work mate. I explained what had happened and he tried to guess who the friend was from my description, and call them. No luck.
What followed was akin to a keystone cops chase with him suggesting every drinking establishment in the area where they could have gone, and us lot having a drink in pretty much all of them.
Eventually we gave up on the grounds of imminent liver failure, but agreed we had got to visit some very interesting and new establishments!
The next day I received a call from the owner, and arranged to return the phone later in the week when I was back in the area, in the mean time I offered to download all the contact details and send them over so she wouldn't be without numbers. She was a little surprised this was even possible, but gratefully accepted.
The phone was eventually returned, and I earned some more beer for my troubles :-)