Geo Talk lets you create a forum centred on any location in the world. The site is a mashup of Google Maps and Disqus which allows a user to create a forum simply by placing a marker on a location in Google Maps.
Each location forum gets a unique URL, which can then be shared with friends or used on a website or blog. Using Geo Talk it is possible to set up a chat room about a bar, cafe, city or any other point of information or location. In fact your chat doesn't have to be about a location, the subject can be anything, it just needs to be centred on a particular location.