Much has been made of GPS-enabled cellphones and the services, such as dodgeball, that they have birthed. Now, you can put yourself on the map from anywhere. Check out plazes. Or, better yet, see it in action at Joi Ito's site.
Could activists use this to help identify clusters of local farmers? What about disease hot spots? Could local philanthropists help community leaders connect with others to build stronger networks? Other ideas...?