This is an interesting little iPod mini accessory from Nyko, a company best known for it’s innovative gaming controllers.
The iBoost Mini is a battery that connects to the bottom of your iPod mini and provides an extra 10 hours of power, you can sync, dock and/or charge the mini with it attached, it doesn’t come off easily so it won’t fall off when you are working out, and it has some smart charging/discharging features:
When it is attached power drains from the iBoost first so your mini’s main battery stays full.
Also when you recharge it the mini’s main battery is charged first, ensuring you always have as full a main battery as possible.
No price announced yet but my guess is that it will be in the $60-80 range.