Xmultiple (http:?/www.xmultiple.com) has released the X-Power 1, an
US$29.95 USB rechargeable battery/backup charge/sync cable for the
iPhone and iPod touch. It’s available in different lengths: six
inches, 20 inches, 30 inches, and in a retractable cable design.

The X-Power 1 is designed to serve as a portable back-up power source
for your iPhone or iPod touch when you intend to go mobile away from
a power source. To use you plug the X-Power1 into a USB outlet and
the X-Power1 charge/sync cable circuitry will charge the Apple device.