While I take sports photos at soccergames, I tend to shoot a lot of photos. For that matter I want quick access to a second CF card. Often I was searching in which pocket I kept that card. It took too much time to look for it and take it out from my pocket
Then I bought a bag that came with an interesting accessory....and it was perfectly made for holding a CF card AND could be attached to the camera strap.
I wonder why they don't sell it separately. I would buy another one or two.