If you've ever had the urge to trace a peculiar Mobile number, you would know what's going through the minds of millions of Americans who try to search for cell numbers every month.
They would have been triggered by

• a suspicious number in their spouse's cellular phone
• an unknown number printed once too often on a detailed bill
• a string of annoying prank calls etc

Either way a person can think of several ways in which he/she could get the job done.
Simply call that number back! This is a terrible step to take.
If the person you are trying to locate is an old buddy from high school, that would be fine.
But if it's your wife's secret lover, it's probably not going to work out well! Look up a Phone book like the White Pages! Phone books only provide Land phone numbers and info on their subscribers.
This simply means that no matter how much you look up white or yellow pages you would not be able trace "wireless" numbers using them.
Refer an Online Directory for Reverse Cellphone lookup! Why is it the BEST option? Now this is the BEST OPTION available today.
They are private online databases which gather information on cellular phone users and provide individuals the facility to access them when the need arises.
This is the best and only practical option out there (private detectives also do it, but for 100s of dollars) if you want to trace cellular numbers because:

1. Its an incredibly fast service providing results within seconds
2. It protects your privacy and is very reliable.
   
3. It is convenient to use and can be accessed from the comforts of your home.
   
4. You can look up as many cell numbers as you wish