I used two 256MB CF and a storage device, Super Digibin on my last two European trips. I was shooting with a Canon S45 and S1 IS. It could handle 10,000+ pictures. I just replaced my S45 with an Olympus E-500. I purchased two 2GB Sandisk Extreme III CF and a Wolverine MVP 60GB storage device ($300).
style="BACKGROUND-COLOR: #000000"The 2GB will hold 140 RAW pictures. I usually take pictures at a site.When done, I upload to the storage device and switch cards to continue shooting. I brought back thousands of pictures in RAW, JPG, etc. formats. The Wolverine even had a viewer LCD that shows both RAW and JPG pictures you took.