Recently I read a Facebook post from a photographer friend who had a computer meltdown. She likely lost over 6,000 of her photos. Her wall post ended with, "I want to vomit." Don't let this happen to you.
I've been testing a user friendly cloud solution that protects your images, and allows you to sync your files between multiple computers! It's called Dropbox and they give you 2 FREE Gigs of storage space with an option to upgrade. I've used a lot of cloud storage solutions (like Mozy) but this is by far the easiest! If you do sign up, please use this link as we'll both get a little extra storage space.
Besides having a secure backup of your files, Dropbox allows you to access your files from any computer. They even have an iPhone app! This basically eliminates the need for flash drives, and cd's.