National Cellular Directory is a website where users can quickly and inexpensively find cell phone numbers. The online directory started in 2006 as an "Opt-In" directory where opted-in National Cellular Directory members can search other opted-in members.
In order to increase the size of the database, the National Cellular Directory started Happy Hour, which allows anyone access to the premium database of cellular phone numbers for one hour each day at no charge. The Directory also has a Reverse Phone Lookup function, where users can enter phone numbers into the Directory and retrieve the numbers' details. The National Cellular Directory can be found at nationalcellulardirectory.com.
Other online cell phone directories include phonesearches.com and fonefinder.net, which require payment to search.