Double Your Battery Life with Belkin's TunePower

"TunePower keeps the music playing even when your Zune player’s internal battery is drained. It offers a great solution for long flights, train rides, hikes--any time you want to extend your music and video playtime."

Belkin's TunePower can help you out with those situations when you're unable to recharge your Zune for extended periods of time.  The TunePower claims a battery life of 6 to 12 hours.  Assuming those specs are 6 hours for video, and 12 for audio, it effectively double's your playtime between charges.  TunePower is essentially a battery back which piggy-backs on your Zune by sapping onto the top and bottom edges of your Zune, and then plugging a small tether cable into your Zune's port.  You can find a review of TunePower on the Gear Diary website here.