What should I do with a wallet I found on the ground three days ago? (details inside)

I found a wallet that contained a small-ish amount of cash (under $100) and a few bank cards in a parking lot this past Saturday morning.

Since there wasn’t a driver’s license I don’t have an address to return it to, but I was able to find a Facebook account based on the name listed on the bank cards. It’s been three days since I sent a message to the guy, and still he has not responded. Same with his twitter account. I even sent a Facebook message to someone listed as one of his relatives, to no avail.

Should I just drop it off at the police department? I really don’t know what to do at this point.

Considering the dude has over 900 friends on FB, I figured he was one of these people that checked his account daily…I guess not.