As of 2015, a subscription service is available for non-smartphone-style cell phones called AccuTracker, which tracks your phone's GPS after registering it to the service. This service has a regular subscription fee. Phones that are too old, however, cannot be tracked via GPS because they lack the functionality.
Smartphones have a number of GPS tracking applications that can be downloaded onto them in order to track them once they have been lost. Some of them run stealthily in the phone's background and only activate when told to from a remote location. DigitalTrends.com recommends an application called Prey, which does the above mentioned functionality. It works for Android and iOS and is compatible with Windows, Macintosh and Linux personal computers.
If a phone is already lost and did not have an application already downloaded onto it, smartphone users have the option to track it down. Android users have access to Plan B, whereas iOS users have access to the Find My iPhone application. Both of these applications use an outside device in order to access the account associated with the smartphone and track the cell phone's location.
If your cell phone is not a smartphone and was not registered for tracking already, it may be a lost cause. The best course of action is to call up the cell phone provider and see if they can track the phone down. This may cost a service fee that varies by service provider.