Watching a 30 min episode of a tv show, uses 25% of my Desire's battery life. Watching a 90 min movie uses 75% (funnily enough!! ) Obviously, powering the lovely screen uses up a lot of juice. Just wondering whether there is any particular type of file that is more CPU intensive to decode and run, than others? I currently use Mpeg 4 format. The program I use to convert my avi's to mpeg4, gives me different quality level options. Would it make a difference to power consumption if I was to convert the avi's to a lower quality mpeg4 file?