LONDON - What do you do if you're stuck in a field at a pop festival but there's trouble ahead because your mobile phone's battery is about to run out?

Thanks to a new gizmo, you now just need to face the music and dance.

Mobile phone operator Orange said on Tuesday it had teamed up with GotWind, a firm specializing in renewable energy, to produce a recharger powered by dance energy alone.

The portable kinetic energy chargers will be given a test run at this year's Glastonbury Festival, the world's biggest greenfield music and arts celebration that begins on a farm in Somerset, southwest England on Friday.

Orange said the prototype chargers weigh the same as a phone and are about the size of a pack of cards.

Attached to the user's arm, they employ a system of weights and magnets which provide an electric current to top up charge in a storage battery. This can then later be used to recharge the phone.

"We wanted to create a fun, engaging and interactive product which would encourage users to have a laugh while charging their mobile phone and at the same time test out a new energy-efficient prototype," said Hattie Magee, Head of Partnerships at Orange UK.

© Reuters 2008