I went ahead and purchased a d2 LaCie hard drive and so far so good. I have created a bootable backup (10.4.5) which i am currently using. I have a few questions in my mind and was wondering if anyone knew the answers. I'll jump straight in... 1) If I use this external hard drive to boot from, will it's life be seriously affected? (consumer user, no heavy apps). Also, will using it in this way save the life of my internal hard drive? 2) My internal drive is 5400 where as this external drive is 7200 rpm. Does the fact that the drive is connected by firewire mean that the whole OS wont experience any speed gains from this extra disk speed? 3) If the firewire cable were to become unattached, would the OS crash or simply jump to the internal, and if it would crash, would this damage any of the hardware? Thanks for any answers anyone can come up with!