Elecom DE-A01D-1908 is a portable battery charger that measures 81 x 35 x 36m and weights 42g. The portable charger is dedicatedly designed for iPhone 4, 3GS and 3G, so you can’t use it to charge your rechargeable batteries, but the versatile battery charger can draw the power of AA batteries and use it to charge your iPhone from 0% to 100%, so if you need to stay in the wild for several days, the portable battery charger may be more practical than a small-size backup battery. Apart from that, the battery charger also comes with on/off switch, while the LED indicator lets you know the charging status.
The Elecom portable battery charger is available in 4 colors, including black, pink, green and white, each one is priced at $49.99 USD. If you’re interested, jump to AudioCubes for more details.