I actually tested this today, idiotically enough. I charged my N800 so it was full up, then stuck it in my pocket all day long so it would be ready to use at an instant's notice! Sure enough, at the end of the day it was completely empty of power because there was enough jostling at my pocket the whole day to activate the screen constantly, so in spite of the fact that I didn't use it one time during the day, all its power was drained.