I brought my Zune with me on a coast-to-coast trip to keep me entertained. The flight was 5 hours long, and I had loaded my Zune with tons of video (movies, TV, etc.). I only made it through one 2.5 hour movie and I received the low battery alert. I switched to music and was able to keep it running until it was time to shut off portable electronic devices, but I really would have preferred another 2 hours of video.
Most of the time I use the Zune at the gym to watch TV or parts of movies while I do my cardio warm-up and then it plays music while I lift, so the battery is fine for this as long as I charge it every other day or so. But on a long trip with no power source, the battery isn't enough for extended video use.
I noticed on Engadget today that Duracel has an extended battery pack for the ipod video (
http://feeds.engadget.com/~r/weblogs...t/~3/71969433/). Anything available for the Zune?