We were watching Modern Family last night and the subject of running/fitness came up for some reason. My wife and I are doing the Amsterdam Marathon (Half in my case) and Oisín had the genius idea that treadmills should be able to imitate any route by changing the incline as you run. Then he suggested showing a map too. We riffed for a few minutes and came up with the ultimate treadmill which need only be a few Euro more than anything already on the market.
So the treadmill would have a microUSB input obeying the Android Open Accessory standard. You would have a cradle to hold an Android Tablet or phone which would be running a massively expanded version of CardioTrainer or RunKeeper. You input "Amsterdam Marathon 2011" on the Android device and you would get a Google Maps Streetview display of the route. The app would then use the Open Accessory input to set the treadmill at whatever your hoped-for speed was and change the incline to match the real route as you progress along. You would then have a very clear idea of what you need to do in order to hit a particular time.
I'd kill for something like that. You could even split the screen between Streetview and whatever TV/movies you normally watch when running on the treadmill.
The only things it couldn't do are downhill, wind and rain. That would be v2.0
Oisín wants to know when he'll get his first check from whoever runs with this idea. He has a 3DS on his shopping list.