backing up digital pictures

I have a 6 megapixel digital camera. Each picture I take uses up around 6 mb of disk space (at the highest quality, RAW format) and I've already shot almost a thousand.

Backing up that amount of data is becoming a royal pain in the butt. CDs are already too small. DVDs will soon be, too, at the rate at which I'm taking pictures. As a temporary measure, I'm storing all the images in my iPod and I will probably have to get an external drive.

My main concern is that soon I'm not going to be able to keep all my pictures in my puny laptop hard drive. I may need to get two external drives, instead, for primary and backup storage.

Or how does a RAID-5 disk array sound?