What about a wireless keyboard and gyroscopic mouse?
www.gyration.com I originally wanted exactly what you want for my HTPC setup, but came across the gyro mouse at a conference and decided to go that route. I'm constantly using the mouse--more than I ever imagined; and it is nice not having it tied to a keyboard. The mouse wouldn't be great for gaming but all other functions are a breeze. Oh, and when you put it down it works just like a normal optical mouse on nearly any surface! Their smaller keyboard is perfect to put away yet also fits nicely on your lap for typing (like now).
