SHARP Aquos 104sh, listen to YouTube with the backlight off? I'm on 4.0.3, trying to listen to music. YouTube is destroying my battery life. I always need to charge my phone at work. If I save the battery, I can work more efficiently, though. Any way to have the best of both worlds? 

On iPhone, you can double tap home and press the play triangle, but that doesn't work on my smart phone. Any ideas?
Try PVSTAR+. Not the easiest UI, but it'll let you play (really just listen to) YouTube videos and a number of other sources, too, in the background.