I've got a new iMac system coming soon which comprises the machine and many, many peripherals - Merry Christmas to me! Included in this little lot are three (count 'em) LaCie Porsche 320Gb USB2 external drives - I'm using one for time machine backup (to match the iMac's 320Gb internal drive), one for windows and one for porn. Sorry, just my sense of humour. Won't need the windows one! Anyhoo, what's your take on powering HDs up and down. With three drives, I know I should power them down each time, but I've had an 80Gb drive recently go belly up and that was sometimes left on, sometimes switched off. Your thoughts?