I don't know anyone who couldn't use this mini battery pack from Kensington. Not only does it power and charge your iPhone or iPod, it's small enough to slip in your purse so you'll always have it with you.

It extends play time up to 30 hours of music (nano 3rd generation only), 6 hours of video, or 3 hours of talk.

The rechargeable lithium-ion polymer battery pack comes with a retractable USB charging cable for recharging the battery pack, and the LED battery meter displays the remaining power level . If you let the battery pack run out you're on your own. $49.99 at Kensington or Amazon.