During Nintendo's GDC conference earlier this week, Masato Kuwahara demonstrated a handful of old GameBoy prototypes.
One of the more interesting revelations was that a Masato had been tinkering with a touchscreen panel for the GameBoy Advance SP, and even a hand-wired Game Boy Camera experiment.
An earlier version of the Game Boy Advance would have followed the classic vertical design - and would have been one fairly chunky piece of kit (pictured next to a DSi, below). Nintendo also showed off what the DSi would have been - a dual slot, chunky DS.
Thanks to N-Europe.