I am planning to buy a MBP this week but, naturally I want to be prepared for it. I'm not foreigner to Macs, I know more about the OS than your average user, but I've never had a Mac laptop. My main question is about "sleep" mode. What happens when the close the lid, etc? I want to know how it behaves compared to my old Windows laptop so I don't go off and leave and come back to find the battery dead. If someone would be so gracious as to describe what actions do what as far as low power modes and how much battery they save (i.e. how long it takes to cause what % discharge) that would be simply amazing. Just to help on what I'm talking about, and what to compare it to, when I close the lid it goes into sleep mode, but I haven't ever really gauged how much power it uses in this state. It wakes back up when the lid is opened. When the power button is clicked once it hibernates, which uses no power at all but still starts back up much faster than a fresh power-up. I don't think it has been fully turned off for quite some time. Thanks again for your help!