well, i guess i'm rubbish then, i save constantly, about every 30 mins is the longest i wait before i click 'save' (and thats on the outside), so that's very clever of me, however i only ever save to my external hard drive when the image is complete, & then i save a flat version & a layered version.
I've tried saving to hard drive more often, but in the interests of safety, i put my hard drive in it's box to try to avoid any problems with it, i never leave it plugged in to my laptop, but i started losing track of where i was on an image.