http://wiki.coworking.info/w/page/16583399/CoworkingAtlanta

Or for more general info look here: http://coworkingregistry.org or the wiki linked above on the frontpage has a list of directories: http://wiki.coworking.info/w/page/16583831/FrontPage

There's also a very helpful Coworking Google Group if you want to explore deeper and find the community.

Highly recommend it - very affordable, and plenty of space to work with.