I remember someone talking about this AGES a go (shut up, no pun intended), and I thought it was funny idea - but I was wondering if it were possible. Now this is all coming from a person with little to no knowledge of the technological field, so bare with me.

But I was wondering if it were possible (and practical, without showing any markings or hints that the case had been altered) to mod a Sega Nomad to instantly dump a rom to a storage medium (flash drive, storage memory, etc) within the Nomad's case as soon as the Nomad is turned on with the game locked onto the cartridge slot. 

No reason for asking, but some people might get an idea. :P

(also, it'd have to be built to fool people - or to make people unsuspecting in every way. that means in look, appearance, and functionality. nothing should give a clear distinction that somethings out of the ordinary)