I usually find that I bring back about 30GB of images from a trip. And since I am shooting a lot at the moment I have about 400GB of RAW files (and growing to backup). At present I have two copies of these on my hard drives and then a third copy of 4.5GB of favourites from each trip backed up twice on DVD.
This is not a perfect system, although I have never lost a file, and I want to get something that will look after me for the next few years. The system I am looking at is a ReadyNAS NV raid system:

http://www.infrant.com/products_ReadyNAS_NV.htm
A friend of mine recommends this one - loaded with 500GB disks. But before I fork out I thought I'd ask if anyone has this, or has something similar they'd recommend instead.
When responding please remember I am an underwater photographer! This means I won't understand tekky answers, I want a reasonably off the shelf solution as I don't have the skills to build something myself, oh and my budget isn't huge as this is being funded out of profit earned from shooting underwater (and that money also has to pay for groceries)!
Thanks
Alex
p.s. Spending this much on storage would sure pay for a lot of film and processing.