My son once left his sneakers in the room, and just a few days later, before he even realized that they were missing, they arrived at our house.
However, another trip he had lost his drivers license in the room and we couldn't find it anywhere. We contacted the front desk at the POR before we left and they said if they found it, they'd mail it to us. Unfortunately this made getting him on the plane on the way home quite a problem!
About a month later, he got an envelope in the mail postmarked Las Vegas with no note or anything, just his license. So who knows what happened to it.