This is so clever:

http://blogs.forum.nokia.com/blog/si...uch-screen-n95

He's not even using any expensive hardware, it's just a TV-Out smartphone plugged into a TV, and a pen with a light on the end of it. The large TV would cost a bit of course, but I suppose this could just as easily work on a smaller set.

The same person invented a way of using a phone camera as a multitouch touchscreen:

http://blogs.forum.nokia.com/blog/si...n95-multitouch

I don't know how practical either of these things are, but they are definitely new ways of thinking about phone hardware.