If you want to experiment with a new driving directions algorithm, it is infinitely more difficult than coming up with an algorithm; you have to hire a lawyer and a sign a contract with a company that collects that data in the country you are developing for. If you want to write an open source TiVo competitor, you need television listings data for every cable provider in the country, but your options are tenuous at best.
So the commercial implications are big. I’d love to see Topographical data be as prevalent on the web as regular mapping data and a Wikipedia for data would be a huge help in that direction. But even non-commercial data would be great to have en masse. Trailguru kind of does this as they allow anyone to upload tracks and waypoints and then plot it on a map.
Any kind of data would be great but GPS data is what’s most interesting to me because it combines geolocation and time, the building blocks for everything. Once you attach your actions (taking a photo, twittering, etc) to that, you can create some really fantastic visualizations.
[tags]GPX, Mapping, Wiki Data[/tags]Tweet