The History of the Game Controller
1up.com has up a feature going through the history of the game controller. Starting in the dark ages of the PDP-1, the article moves all the way up to Nintendo's mysterious Revolution controller. From the article: "And when will Nintendo tip its hand? All we know at this point is that the Revolution will be backwards compatible with GameCube controllers, so at the very least the system will support all the functionality you're used to. But apart from that, will the controller feature a built-in touch screen and microphone, like the Nintendo DS? Is it just a box of brain-wave-reading goo? One thing is for sure: if history is any indication, there's no telling what the game controller we use twenty years from now will look like. And just as long as there's no numeric keypad, we should be okay."
Here's a link to a fairly comprehensive video game controller family tree (complete with thumbnails).
http://www.axess.com/twilight/console/
The article just seemed a little too verbal when a good summary graphic could have guided readers that might not have a clue about some of those systems.