Applications to locate friends and places were among the features of the latest mobile phones on show at this year’s Mobile World Congress.

Both Sony Ericsson and LG launched handsets with built-in sat nav at the event in Barcelona.

Nokia, which has already incorporated GPS into its N95 handset, announced a deal with mapping company Navteq that will give its series 60 and 40 phones digital maps.

The theme continued with the launch of Gypsii, a location-based social networking service which lets people use their mobile phones to track down friends - something trend analysts at mobile consultancy Aircom predict will take off.

Even Garmin, more usually associated with in-car and handheld sat-nav devices got in on the act with its announcement of its touchscreen Nuvifone. This combines a mobile phone and navigator.

However, it wasn’t all about location, location, location.

Mike Short, chair of the UK Mobile Data Association, predicted that Facebook and Myspace would make it easier to access social-networking sites using mobile phones. This included better applications for uploading video and pictures.

It went from social networking to social conscience with Trevor Baylis, the British inventor behind the clockwork radio displaying his Eco Media Player.

The environmentally friendly music player can be used as a phone and hold up to 500 songs. The battery is said to last for up to 20 hours and winding it for a minute produces enough charge for a claimed 40 minutes of playback. It costs £140.