A Storage Solution for Lots of Digital Photos?

Duizendstra asks: "I've been asked to explore the digital storage possibilities for a professional photographer. One of the characteristics is the rapid growth of the amount, and size of pictures. At the moment, one photo session produces about 2 GB of raw data. He has an Apple - Power Mac G5, and he currently uses DVD as his storage medium. However, he has lost quite a few photos because of DVDs that can't be read anymore. I would like to know if any Slashdot readers have any experience in creating a solution for such a problem? Any help/idea(s) would be greatly appreciated!"