This is pretty crazy. Sharp has shown a prototype for a new model in thier Zaraus line of PDAs. The Zaraus runs Linux OS. This new model has a clamshell design with a full keyboard (small size) and a 640×480 screen. It appears that the handheld will be able to operate in keyboard (landscape) mode, and by twisting the screen around and folding the unit shut, similar to the Sony NR/NX series of PalmOS handhelds, the unit would operate in a tablit mode. The unit uses a CG Silicon display, which was developed by Sharp. This type of display can have twice as many pixels in the same space as a TFT display, and consume less power. Sounds like a winner to me!
Read more about it at Brighthand.com http://www.brighthand.com/article/Sharp_Clamshell_Zaurus_Demoed