Sounds like a great idea, but why limit to twitter- and you will probably run into some cases where usernames are already taken. Why not just create a site to report nuts drivers by license number. Then parents, etc. could look on it for their license number to see what their kids are up to. This would be a lot easier than the solutions that involve additions to cars to track their children. Then hook it up to twitter, facebook, etc. Of course, there are probably already sites that do this, but maybe you could do it better.