I have found that lot of people are trying to collect free geographic data, using GPS or whatever. I like the idea very much and I played myself with the tought of buying a GPS and create a common database for people to insert ther data.
So far I'm trying to collect links on such projects to have a better Idea of how far they have got, and what interface they give for people who want to use their data. I'm also interested in open source application providing ways of visualising this data.