shut it off if I'm not using it for a day or so or when it is running very low on charge, otherwise I sleep it through the day. As an above poster said, it only takes like 15 seconds to boot so it really doesn't matter if I turn it off. Also, it is still using battery while it sleeps (yes it's small but it still uses power.) And when it's off... no power used. I find that when I do use it, I often use it for a long time, unplugged and I want all the available battery power I can get so turning it off makes sure I have all the power I can when I do use it.