Glyn Evans of Pocket PC Solutions has developed a prototype keyboard that also acts as a case for a UMPC device. Imagine that you pull your UMPC out of this case, connect it to the said case and start typing away. The keyboard makes audible clicks you press keys. The prototype was built using technology from Eleksen, the company that came up with flexible fabric keyboards.
Pictures show the UMPC in the case and then with the case acting as the keyboard.
This prototype clearly shows that fabric keyboards may be one solution that combine light weight and small size with all the advantages of full size keyboards.