Nike has announced that its Nike+ application no longer uses a sensor in your trainer to monitor your exercise details. They've now moved over to using GPS and the accelerometer in your iPhone.

This is good news for all the fitness-freaks and serious runners out there because you previously had to buy a special sensor and it was notoriously unreliable. The only downside to this new system is that you have to take your iPhone on a run with you, but that's no problem because you probably use it to play music anyway.

The Nike+ application monitors your time, distance, speed and calories burned when your running or walking and it also maps your running route. Other features of the application include voice-encouragement which motivates you to keep going when you get tired, a power-song which also gives you a lift and and the option to see on a map where you've run.

You can also log-on to Nikeplus.com to set goals, take part in challenges and share you runs with others.

The application costs £1.19 and is available to download from the App Store and works on all iPhone running on iOS4.(Click here to download)