I distinctly remember reading about Atari's ST Book, the follow-up to Stacy, back in 1991 and seeing it as a truly exotic, truly awe-inspiring machine that was beyond the reach of mere mortals. Apparently it was too, as Atari fumbled with it and only managed to sell a few thousand ST Books at best, effectively turning this lovely laptop into quite a collectible. The machine, mind, was very powerful for its time and size -easily bettering the STe- sported a sharp screen and was actually really portable. You can find out more about it here, here and here.
Oh, and I wouldn't be mentioning it if it weren't for this Atari ST Book auction over at eBay. Keep in mind that you will be bidding on an untested computer (lack of a power supply can be a nasty thing), but also probably grabbing it for much cheaper than is customary. Seller ships worldwide! Oh, and good luck too.