Joystiq sister site Engadget recently unearthed a great Nintendo patent filed way back in 2001 for an "Electronic apparatus having game and telephone functions" -- that's right, plans for a gaming cell phone from Nintendo. Mock-up pictures of the device show a small, Game Boy-style D-pad and buttons atop a standard 12-button cell phone layout, along with sketches of a game of "Super Mario DX" being interrupted by an incoming call.
While the failure of the N-Gage and the current success of the Nintendo DS make it somewhat unlikely we'll see any actual products created from this patent anytime soon, it's still interesting to note that Nintendo included cell phones in its mobile gaming plans, at least at some point.
Nintendo Game Boy 1st-gen
Nokia N-Gage 1st-gen