We are students from Budapest, Hungary, and this is a university project for a .net course.
We develop a public traffic tracker applications for Windows Phone 7 devices, that can give information about the actual positions of the nearest vehicle on a given line. The speciality is that we use only the GPS information of the users' WP7 devices, so this is a completely software solution without any hardware investment. The disatvantage is that for the real operation we would need a lot of active WP7 user.
For documentation we use hungarian language.
A test version of the Application can be found here:
http://ptt.somee.com/WCF Service address for tracking the lines:
http://ptt.somee.com/InfoService.svc