3 or 4 Screens
Most people need 3 screens.
One for their desk. Work, news, communication, art.
One for their living room. TV, movies, slideshows, gaming.
One for their pocket. Previously communication, but now everything really.
Maybe some people (@sethkjolly) want some sort of couch device. A tablet or whatever.
There’s just not room in the long run for more than 4 screens tops per person. And even in the case of the living room probably not more than one computer tied to each screen eventually.
More: Jason Kottke describes how the adaptability of the iPhone makes it a perfect gadget slayer.