Ah, I understand what you mean now.
It does sound like an intriguing idea, but in the short term some sort of UMPC might be the closest you'd get.
I was looking at an
OQO in a store recently (the original one, not the new model they just released), and was struck by how much it looked like a Palm LifeDrive, it's just a little larger in all dimensions (and has only slightly worse battery life). That might get you what you need, functionally, but the price tag is kinda high just for that purpose $1.5k~$2k