Create a group called 'camera' and add your user to it.
Then do the following:
Code:
/usr/lib/libgphoto2/print-usb-usermap > /etc/hotplug/usb/usbcam.usermap
and make the owner of usbcam.usermap your user.
Code:
cp /usr/doc/libgphoto2/linux-hotplug/usbcam.group /etc/hotplug/usb/usbcam
and make usbcam executable.
DigiKam should now work for your user.
MagicMan