Mobile application Fellow Traveler

Last weekend we have traveled from the forest to the city. We stand at bus stop and I have notices that most 4 passengers cars are filled wih 2 people. Thats a huge waste of resources. A lot of people are standing at the bus stop and here in Ukraine buses are overfilled and totally unsafe. What if to create mobile application ( Windows phone for example ), where people can share where they want to travel and drivers read this data wia 3G or bluetooth or EDGE and can take additional passenger for speciefed price - some kind of peer-to-peer taxi. That can save tonns of fuels and cars per year.