Firebox is offering an iPhone power pack - the MiLi - that actually manages to incorporate a bit of style.

An ultra thin protective case with a built-in battery, the MiLi is rechargeable via USB and offers twice the battery life of the iPhone with up to 390 hours standby time.

with an LED display to show charged-ness, the MiLi can charge other USB gadgets too. It's on sale now in black, black and green and white and grey for £49.95.