Instant Reverse Phone Lookup

I had someone call me from a cell phone that came up as unlisted. Can you reverse lookup a cell phone number for free? I see a lot of cell phone number lookup sites but they all seem to charge for the service.

my friend is being divorced…can her husband’s lawyer trace numbers on her cell phone bill to find out who she’s been talking to?

I am looking for a reverse cell phone lookup service which will give me the exact location of a cell phone number. Name and address I will pay for.