Personal Rapid Transit
This Personal Rapid Transit (PRT) proposal is still one of the coolest ideas for improving the commuting situation that I have seen. Microsoft has a really large corporate campus with buildings spread out over many square miles. Going to meetings in another building today involves driving yourself, taking a campus bus or walking. Given the choice I'd walk rain or shine, but often you don't have enough time to leave the extra 10 - 20 minutes at each end of the meeting. And some buildings are too far away to walk too.
In any case, I'd like to see a system like this adopted for an even wider audience than just one company. Wouldn't it be great to be able to get on one of these at the end of your road and shoot all the way to work or into town. It would beat the pants of today's grubby and inconvenient mass transit systems.