What plazes actually does is automatically detect an user's location and connect the user to people and places nearby. Users can relate to locations by adding pictures, comments and reviews.

Firstly, plazes will try to guess where the user are by identifying the network address. If it's not correct, users are able to update the guess.

To check in to a place, an user needs a program called Plazer which helps to:

• - List your online buddies where they are
• - Add new Plazes
• - Automatically check in at Plazes
• - Conveniently edit Plazes descriptions
• - Add your current location to applications like Skype, Google Earth, AIM and more.

Plazes also includes a service where users are able to mesh their Flickr pictures together with Plazes. Earn karma points when you discover a plaze to get in the top discoverer's list. Users are also allowed to build stuff on top of Plazes with the API provided. Build your own map, import it into a calendar and even show the current Plaze info in a blog.

Here's an example screenshot of plazes.

Plazes.com
Sharing and tracking your locations. Currently in beta.