Can someone explain to me how this will work with a MBP? I understand to use Time Machine, I will need to purchase an external hard drive....fine. I understand once I plug in the HD, Leopard will ask if I want to use this HD for Time Machine, which I'll click "yes"...fine. Now, Time Machine will do a full system backup and will continue to do so hourly as it has been stated...BUT, my mac is a LAPTOP! I move around all the time with it....couch, toilet, work, airplane, bedroom, hotel, etc. Obviously Time Machine will not be backing up my system when I unplug the HD, right? So, when does Time Machine actually backup?....Does it back up every time I plug in the HD? So, if I have my MBP plugged into the charger and the external HD, Time Machine is bakcking up, correct/incorrect? When I go to another room and unplug the MBP and HD, Time Machine stops backing up, correct/incorrect? Say, 15 minutes later I plug my MBP and HD back in, does Time Maching begin backing up again? I just need to understand the system of how I should be using the MBP and Time Maching and the External HD all together effectively.