Yelp!

A great example of a Web 2.0 company is Yelp! This site is, at a basic level, a search site that allows you to find different companies by location or type. While this doesn't seem much more than Google Local or Live Local, it adds a very unique social networking aspect. Users can create accounts and review any restaurant/business that they have visited. In addition, they can communicate with other users, asking direct questions to people who have reviewed a particular establishment, looking for advice, or just to talk.