Police in Hertfordshire are now using GPS technology to help locate lost and stolen smartphones.
Hertfordshire Constabulary said technology can help officers track down phones, which have apps downloaded that are activated remotely.
Free apps are available to download on most smartphones such as iPhones and BlackBerrys and can also now enable a phone to be tracked for the police control room.
However officers urged people who think their phone may have been stolen not to try and track it down themselves but call the police.
DI Paul Doran, from the Crime Reduction Unit said: "We are encouraging all smartphone owners to download an app for tracing your phone. Then, if it is lost or stolen, it is much more likely that you can get it back.
"Even if your phone is covered by insurance and you can get a replacement, losing all your contacts and other personal details can be devastating.
"These new applications are very useful tools for tracking down stolen goods and catching criminals in the act. If owners report thefts quickly enough there’s a better chance of getting their phones back and for us to catch the perpetrators before they have disposed of any evidence.
"This technology can have other uses for the police such as tracing missing persons, and we would urge families with vulnerable members to securely record their account details which are required to activate this facility."