What with the fact that every member of British society and their pet gerbil has an MP3 player, we're seeing more and more of these fancy battery backup devices whizzing around.
This is perhaps the neatest, and most environmentally friendly of the lot, packing a rechargeable battery and a pair of solar panels in one slimline device.
The backup battery can be charged either via standard DC-in, car cigarette lighter or by exposing the panels to either ambient or direct sunlight. So, even on those long weekends out in the sticks, you'll never be without enough juice to make an emergency phone call or top up your MP3 player.
The Opti-UPS charger has a standard selection of power adaptors, including female USB and male mini USB. While it's unlikely to completely recharge your mobile, the solar option makes this an extremely impressive bit of kit.