Habitat Perspectives by Marcos Weskamp is one of the 2 best shots at trying to link place and space with the participation of people. SuperFuture being the other one.

Imagine if both could become one?! If you have a GPS equipped mobile phone you can take part in this new adventure. Let's anotat"ing" the world.
Marcos' HP is only a preliminary release at the moment and as people help for the content and coding stream in (source code will soon be released), we will be able to add a whole host of new features. At the moment, to echo some of Adam's ideas, I think the service needs to be viewable on a mobile phone "to close the loop", and let's make it available for people to comment on those places. It's all nice to have a picture of a restaurant but it's even better if people can leave there impression about the place and recommend it (or not) to other people, or recommend an exhibition to other people passing by, or let you know about a spot in town that you'd better avoid going to or that you'd never imagine was so cool. Imagine when those spots will become little tickles in your pocket as you walk in the city. You could set your GPS cellphone to alert you when you pass nearby a spot that has been rated 4 stars or more by the participants or equally rated as dangerous by people.
Then we would need to be able to tag those spot by category and a whole new level of infos could become viewable. Let's only show the pictures posted from that time to that time, or from that one participant or from that one area, or only related to museums, or only highly recommended places, etc... Possibilities become endless and ways to view the cities too, that will provide us with brand new ways to view a city and its informations, and all that will be done by the people. hunnnnn.
Can't wait to help out!