I used to think that I should just get the cheapest one out there. Then I thought ok, what about the fastest one? And then I ran into another very “scientific” article. I appreciate Rob Galbraith’s work on this subject. He took out a lot of the guess work for me. He takes into account the speed of your camera bus and then the speed of your card. Right now I’m using a Transcend 4GB 300x and my backup is an Sandisk Extreme III. Usually I’m OK unless I decide to shoot RAW. Then I really choose my shots more carefully or I end up doing a lot more deleting on the fly.