Originally Posted by JSWolf
A battery extender is a device that plugs into some other battery powered device to allow you to run the device or charge it.
It uses 4 AA batteries and costs $20.
When you use the wifi, it drains the battery even more.
I have this and, unless they've fixed it, there is a small caveat. You really can't use rechargeable batteries with the iPod touch, because they provide (1.2 times 4) 4.8V. The Touch is very fussy about its input voltage, and 4.8 is not quite enough to make it happy. If you use Alkaline batteries, it works just fine (4.5 times 4) 6V..the battery pack takes this down to standard USB 5V before passing it onto the device.
I like using lithium AAs in mine actually, they're more expensive than alkalines but they last FOREVER...and the Touch is happy as a clam with this setup.
And for more good news, they also sell a tip that will charge your Kindle using this battery pack!