Some services are okay, a lot of them are poor, and only one has left me extremely satisfied. If you have in your possession a phone number but you don't know who it belongs to you can use a reverse cell phone directory to track down information on the owner.
You can find directions to almost anywhere, and you can find recipes for any type of meal you wish to try. That is why the only reliable and guaranteed reverse cell phone look up sites are those that require you to sign up as a member for a very small fee. This is beneficial if you're worried about a cheating spouse, prank callers or who kids are calling.
There aren't any national or state wide directories to allow you to trace a cell phone number and therefore they cannot include it among their free services. Some service providers can trace a home phone number but can't trace a cell phone number. Whatever number you may have, you can always try this site for a reverse number service.
So, get out there and find it. You can use this system to find out who is calling your phone.