Check the contacts stored in said phone & look for "ICE=in case of emergency" if it is there call it & explain the situation. Many phones have the owners' home # on the face of phone. Or take it into the service provider which should be obvious and take it in to them & request they get it back to its owner...be sure to obtain a receipt. Or look up the name you have in a local phone book. IMPORTANT: Keep it turned on & with you as I am sure they will be calling you...might I add that it is a very nice thing of you to do & be concerned about.♥
Give to police and they can track it's owner. I've found a couple of phones before and I just called ppl in the address book and described the phone till someone recognized it as being a lost one.Try mum/dad bro/sis type contacts first or "work" that's what I did and got 2/2 returns.
You can get it by their service provider
The only way is to do it is google it an then you got to pay to get the info
Actually you can get the address information of that person from the servuce provider. However normally they don't divulge this information. You can call on the number stored in the cell phone and then find out from a relative of friend of his.