Treeplane is a project that we were developing in order to present it at Microsoft's contest Imagine Cup.
The basic idea is to create a service for navigation on public transport, with full assisted navigation, spots of interest, changes of transport, and everithing that may be useful to traveler.
You can say: yes, but alredy exist services like this!
Yes, but for these services the bigger problem is the data! Who will insert data? Both solutions (travel companies or the service owner) are bad for some thing... Why don't permit to community to insert data itself, for example like Wikipedia?
Because you can't verify that inserted data is right!
Yes, with our algorithms! :)