CF cards for 7D
I have a 7D and had both 20MB/s and 30MB/s Sandisk Extreme III cards from when I had my 40D. They worked fine, but I recently bought the new Sandisk Extreme 60MB/s card and I have noticed a distinct improvement in the time it takes for the buffer to clear and when downloading photos to my computer. The 7D's large 20-30MB files are best handled by a fast UDMA card IMO. I'm not sure if it's worth buying into the ultra-fast (ultra $$$) Extreme PRO or similar cards, but it's possible.