Back in 1979, Atari came up with a design for a next-generation console called the "Cosmos" (you'll find it on this list of handheld games consoles. This remarkable device, planned for release in the early 80's, would have used holographic games in order to give an illusion of 3D, all in a hand-held unit.
In any case; only five prototypes were ever built (and only two of those ever had their electronics put in)... but one of "the three" has come up for sale on eBay on Buy It Now. I kid you not. Price is just short of ยฃ10,000. Don't you just want one?
- AtariMuseum's page on the Atari Cosmos - with piccies; fab!
It actually looks kind of lame if you ask me, but I guess it was 1981.
aaaaaaaaaaah! Where are the others? I bet someone in/who used to work for Atari has them...