I’ve never used this, as I bought it, and then decided to buy an epson P2000 rather than an ipod!
You can use this with any photo / video / (non photo) click wheel ipod. It connects to your camera and allows you to use your ipod as a portable hard disk. So if you have a 60GB ipod with 20GB free space, then fill it with photos when you’re on holidays and need some extra storage space.