One of the worst things that can happen to any artists is to lose your work to a corrupted file, a power outage, or storage device failure. It’s happened to me several times, and now I back up my novel in several places.
1) I have Dropbox set up on my computer. It automatically syncs my files stored in its folder, without me even having to think about it. I can access it across multiple computers, or log in online anywhere I have net access. 2 GB free. If you get referrals (such as with my link right here) you can earn another full GB of free storage. They also offer paid accounts up to 100 GB, I think it is.
2) USB stick. I keep a 2 GB drive handy at all times. It’s nice to have, but they’re losable. In fact, I’m missing one now, and it’s annoying me.
3) Google Docs – it tends to muck up your formatting, but it’s perfect for writing from anywhere, and making backups. better to have to redo your tabs than to lose it completely, eh? It’s also great if you want to share your writing with a few people for critique or collaboration.
4) Backup to another partition on my laptop.
5) Email it to myself.
Backing up is vital… I lost over 30k on my original NaNoWriMo novel, and I’m missing about 20k on the one from two years ago. It makes me very annoyed, and if I’d been more diligent about my backups… I’d still have it.