Foursquare comes from ex-Googler Dennis Crowley who also created the now defunct Dodgeball. He describes Foursquare as being “50% friend-finder, 30% social cityguide, 20% nightlife game”.

Whilst the main social networks try to expand their reach as far as possible some are looking at more specialised niches. One of these is Cooltribe which describes itself as “the social networking site dedicated to connecting like minded people around the world who care for the environment, fight global warming and other ethical issues”.
As [...]