I've always said that video footage doesn't exist until it's in at least two places. Backing up is essential, and you should create those backups just as soon as you can after shooting the original material. I'm using and loving Offload from Red Giant for making backups quickly and simply and giving me peace of mind in knowing that the stuff I've shot is safe in two places. Here's a look at how I use it in the production workflow here at Geeks Life.