Luna: From what I remember, the RSMMC card won't be detected if the cover is open. You could probably file it off and push in the hinge to trigger the switch (if that's the case) but then it'd be exposed all the time.

That picture is exactly what I had in mind, using the cover as a stabilizer is an excellent idea.

Will USB keyboards work? Might just be a matter of dissecting an off the shelf product and packaging it right.