Back up now.
Three ways to recover quickly from a computer crash,
1) Use www.mozy.com which is an online backup service. Once it's setup, you don't have to worry about it again. Free for 2 gigs. A low tech curve, high result.
2) Back up to some drive, usb or otherwise. The easiest way to do this is use www.goodsync.com
which syncs two drives or folders as you specify. Again, once setup very very easy to use.
3) Use Google Docs. Doesn't matter what computer you're on.