Can anyone tell me why the Canon D40 and D50 use compact flash cards, but the Rebels use the SD type? I was just wondering since I am really thinking about stepping up to the DSLR and trying to weigh all my options... And we have several SD cards since we have 2 point and shoot digitals

My rebel xti uses CF.

The Rebel XSI uses SD and the 40D and 50D use the CF. But CF cards aren't expensive. I got a 4GB for like $30.

The reason why (I think) is because they are faster, and camera that have a higher fps rate need a faster write speed. <BR> <BR>Someone correct me if I am wrong.

Riley I think your right and even within the CF cards available there are different speeds of write rates from what I was told.

YEah if you are going to shoot raw and jpeg at the same time and shoot sequences you want the fastest you can get. <BR> <BR>I got an 8 gig screamer for like $160.00 worth every penny!

CF cards are currently the standard when it comes to DSLRs, only the new Rebel uses SD AFIK. I think that is still partially due to their more robust form factor and because they are usually the first to come out in larger capacities with more throughput. You'll probably see more mfg's switching to SD however. <BR> <BR>I personally don't like SD cards, they seem too small and flimsy. I had one of my CF cards go through the washer and dryer in my pants pocket yet it still worked perfectly and had all the files intact I had shot that day.