Controlling a USB device from an Android Phone

[rh4games]

is it at all possible to control a USB device from an Android Phone App?

For example, amongst other devices, I would like to connect an external camera to my Android phone and take the pictures and transfer them to the Android phone without transferring memory cards; the reason I'm using an external camera is because of the quality of the pictures and the flexibility to use different lenses.

Thanks

rh4games