I am thinking of buying a harddisk case for my laptop harddisk. It is possible to use this as a portable storage for digital photo - transfer photo directly from digicam to harddisk using mini usb connection.
You need a portable storage such as XDrive, which has an internal HDD, USB interface to connect to the host PC, and an interface to read the pictures from your CF (or other media cards) and transfr them to the HDD.
A portable USB drive only has a USB connection to the host PC, and it cannot talk directly to the digicam, even though the camera have a USB interface also.
Maybe some camera manufacturer will come up with a camera with high speed USB host interface that will allow you to connect a USB drive directly to the camera. Presently I have not heard of such a camera.