A Stone Age Nintendo DS
I did a double-take when I saw a page dedicated to the Nintendo Game & Watch device. These were single-game portable devices which also happened to be, you know, watches.So pretty cool, right? Nintendo stuff from any decade is fun. Ah, but wait. When was the last time you saw one of these things? Let's look at, oh, I don't know, the Donkey Kong II model.
(image from here)
Now I have your attention, right? Twenty-five years before the DS came out, Nintendo already had a dual-screen portable device. Nintendo was ahead of its own time. To be fair, a modern microwave likely has more processing power than this thing. But still.
I originally found this at The Best Stuff in the World, and Wikipedia has more. I also realize this may not be news.

A Stone Age Nintendo DS
Posted Nov 30, 2006 — 6 comments below
Posted Nov 30, 2006 — 6 comments below
Gavin — Nov 30, 06 2517
Ben — Nov 30, 06 2518
apican — Nov 30, 06 2519
Scott Stevenson — Nov 30, 06 2521
If you can find a Game and Watch version of Brain Age, let me know. :)
Joachim Bengtsson — Dec 04, 06 2555
Alastair Tse — Dec 04, 06 2557
Game Gear :)
At the end of the day, there are only so many ways latches and hinges can be arranged to give you portability. Hurray for copying ideas.