IBM's MetaPad concept
Back in 2007 I had what I thought at the time was a unique brainstorm in the area of computing and communications. Noting the quickening convergence between PCs and cell phones, I suggested that the obvious next step would be to bridge the two in a way that had not yet been done: shrink the PC down to a credit-card sized contraption about 5 mm or so thick and encapsulate it in a format that allowed it to be plugged in, PC card style, into an array of device “skins”. In essence, a core engine that could drive your cell phone, GPS device, netbook or even desktop PC. The skin, or shell, would contain or connect to all of the audiovisual interfaces and the main power supply… although the engine would of course have to possess its own energy storage for transport between uses.
Tabula Crypticum 