Foot-powered battery pumps, wellies that charge while you walk - and now, a T-shirt that can beef up your mobile's battery.
Orange has a pedigree in coming up with eco-friendly (and innovative) ways of charging your mobile when tramping around a festival. Sound Charge is its latest, a shirt embedded with an A4 panel that picks up soundwaves and converts them into an electrical charge. This then goes into an integrated battery that can charge most types of phone.
Sounds cool - though like Orange's other eco-charging ventures, it's just a prototype, so will only be available at Glastonbury, of which Orange is a sponsor.
The development team estimates you can get enough charge for one smartphone over the weekend, based on sound levels of 80dB (around that of a busy street).
This shirt-device is water-resistant so you'll probably be able to withstand a small drizzle - though we're told by Orange that 'there is plenty of indoor music on offer at the festival should there be a period of rain'. Just make sure you remove the sound panel before throwing the shirt in the wash.