Take a look at this image please...
http://www.geekologie.com/2008/06/30/buzzball-1.jpg
Have you ever seen those toy balls which you roll across the floor and they remain upright? Well, I was thinking, if they made giant versions of these which are able to fit a few people inside, this could be the next new car! We could all be rolling around in balls going at very fast speeds without the hassle of a traffic jam. Of course, they'd all be on rails so they don't roll off somewhere. The weight on the inside underneath the seat will keep them upright at all times. Some kind of computer system will stop the balls from hitting each other, slowing and speeding up when necessary. They'll also save energy when going down hill, apart from when they have to brake, lol. The ball will be big enough to fit two other passengers as well as a driver. No driving test required since everything is on rails anyway. Completely safe as you can't crash and even if you did you'd be protected more than a normal car. Speeds in excess of 200mph on straight highways.
I know, what a load of balls. 