It is a no-brainer on how much greener the earth will get if folks start using public transport where possible. Interesting ways to encourage people to board that bus or railway train will help reduce emissions. It also helps improve health since you need to walk at least a few steps farther than the garage to the bus or train stop. Location based services uses location of a mobile to deliver value added services.
I am impressed by this game that Bay Area public transport authorities have started to encourage usage of public transport systems. Reached this location from NewYork Times BITS page.
Countries like the US, where urban dependence on public transport is pretty low, do need such initiatives. Particularly impressive is the use of the location based technology. What makes you play this game are incentives such as "being a Mayor gets you some freebies".