I just got a new MBP and I'm just curious as to what everyone does when they are done with their laptop. Do you just close the lid and let the laptop go to sleep until your next session or do you completely shut down. I found myself shutting down every time I was done and went to the Apple store the other day and this kid tells me it's safe and easier to just shut your lid and put the computer into it's sleep mode until you're ready to use it again. This is convenient but is it good for battery life?