Ooh I would be interested too if renaming /system/media/audio/ui/TW_Low_Battery.ogg would work, without any adverse consequences...but I am a little too inexperienced to get out of trouble to try.
I also have a question about the ability to use the camera and music player. Is what was said about the built in fail safe that turns off the camera when battery is low, only for those who are on the stock rom? Which leads me to ask are there roms that allow the use of the camera right up till zero percent battery?