For a multimedia keyboard that I use all the time on *both* my HTPCs I recommend the Adesso WKB-4000US. Basically a wireless with great range that is the bottom half of a laptop. The 52" LCD and 106" projector is the other half :D. A one piece solution in a form factor that most people are used to and the keyboard is large enough to be usable. http://www.adesso.com/products_detail.asp?productid=281

"Transition" devices have been available for years. I know we've had them for the last 6 or so: http://www.gyration.com/ I don't think I have seen anyone use them off the table. Waving it around in the air is way too imprecise and tiring.