Open source projects overview

my question is not directly related to linux, but I didn't find an
appropriate group (please tell me, if you know one), and I think Linux
users might be most supportive.

I am impressed by the progress of projects like (Free
Wifi community), (Worldwide streetmap), (data collection for speaker independent speech
recognition) and others.

Do you know a list of similar projects where a community of people
shares data or services that you usually have to pay for continuous or
expensive fees? Of course there ist with a list of some
million opensource projects, but I'd like to participate in projects
that go beyond the development of software like the three examples