While municipal data can support the creation of new media tools that can cities work better, it’s also worthwhile to remember that civic-minded developers can also build tools that make life easier for citizens without any government cooperation at all.

One recent case in point is the emergence of several web and mobile phone applications that are aimed at helping urban dwellers split the cost, and environmental impact, of a cab ride.

In New York City, two new applications have launched in the past month – Fare/Share, a mobile-enabled web application, and Weeels, which is an iPhone application. Both of these work in similar ways – asking people to enter their origin and destination and then matching them with other folks going the same way. The tools also come with handy fare calculator tools, and a way to submit feedback about the ride experience.

The shared cab phenomenon isn’t limited to New York City, either. Ride Penguin is another application launched earlier this year that helps people share taxis to and from the airport in Seattle, Washington and Las Vegas, Nevada. And U.K.-based airline Virgin Atlantic has helped launch a service that lets its passengers share a cab to their destination.

All of these apps depend not on government-collected data, but information shared among people.

Of course, if and when the shared use of taxis becomes widespread, there likely will be a role for government in rethinking the structure of regulated taxi fares. New York City has already introduced a group fare pilot program to this effect to support its efforts to promote morning rush hour taxi pools from certain points in the city.