I think one of the hurdles is timing.
When I connect the N9 to my notebook and turn on the notebook,
I can choose "Use as mass storage" after a couple of seconds on
my N9.
I can then press a key (ESC in my case) on my notebook for selecting
the boot device.
So the bios has to do a scan of USB-ports between selecting mass storage
on my N9 and pressing ESC on my notebook.

Unfortunately my N9 is the only phone I've got, so I don't want to brick it.
That's why I'm asking whether anyone has tried it.

Is there a way to put the N9 into mass storage mode by command or does
it have to have a signal on the USB-port for mass storage mode ?