As back-up batteries go, few are as cool as this one. It is small & light, and has a solar panel built-in so you can get a charge just about everywhere you go.

Easy to charge... leave it in a sunny window, or plug it into your computer's USB port using your Apple iPhone/iPod sync cable (there is a port for your sync cable on the back-end of the charger). Once charged, take it with you for a convenient back-up power supply for your iPod or iPhone.

Safe? Yes! The voltage is regulated, and delivered from the on-board battery. Changes in sunlight only affects how fast it charges itself, not the voltage, so like all other solar devices, there are no surges or spikes.
We've used this charger on our own iPod Touch Gen 3, and it works great. The connector fits well, and does not slip.

SPECIFICATIONS...

Dimension(L x W x T): 2.25 x 1.4 x 0.51inch

Capacity: 500mAh (approx 2/3 the capacity of your iPhone battery)

Voltage: 5.5V USB-compatible

Color: White and black

Material: ABS plastic

Compatible with iPhone / iPod series