The MGB111 is the 3.5" disk version of the MGB100 so most of the software works fine on both. However you cannot flash an image from one machine on the other since the hardware is slightly different... the images that come for the MGB111, for instance at:
http://mgb111.pradnik.net/en.htmcome with a selection of software that requires libraries, so when you try out sofware compiled for a MGB111 (for instance midnight commander) when you try to run it, it will complain about missing libraries on your MGB100. Luckily the webmaster of the URL above also supplies most of the libraries separately also. So most of the software can be made to work but it requires some trial and error. No harm done however; you can't damage your MGB100 experimenting within user space (linux term for applications) unless trying to flash wrong firmware for instance.
Using the MGB100 as an USB storage device is sort of implemented; if a device such as a harddisk or usb stick is connected to it, the MGB100 can copy the contents of that device to the harddisk of the MGB100 by pressing the backup button (see manual). So if you have a camera of which the storage 'emulates' a harddisk or usb stick; i.e. when you connect it to a PC the internal storage of the camera is mounted as a drive, then connecting it to the MGB100 and pressing the backup button should do the trick.
If some sort of protocol however is used to transfer content from the camera to external storage then it is a lot more difficult...
