Mobile number locator?
Please better describe what you want to accomplish, but I have a feeling what your asking is not something that should not be discussed on a public forum because its probably illegal.
If you want to find a cell phone number try 411, if you want to find where one of your phones is android, apple, windows, and blackberry all have software that can do this in their respective stores/markets.
If you want to track someone else's cell phone apply for a job with the CIA, DHS, NSA, FBI or just keep asking questions along the above lines and i'm sure one of them will come find you.
p.s. don't worry, Just because you made your tom's account today to ask questions about illegal activities doesn't mean your IP address...