With AVCHD camera, what is the best way to archive the original footage should you want to access it again -- create a disk image and select an external drive as the target? I've yet to work much with DMG files other than for app downloads. Is there anyway split the data to fit on a DVD? I'll be using 8-16gb cards (4gb would certainly fit on a DVD, but I'm not sure I'd want to deal with only 30 minutes of video on a card).