If you register with the site, you can create your own account where you can upload your own content. For profs who want to use this as part of their teaching, you can grant access to portions of your account to groups (a class for instance), where they will be able to view and interact with your content. For example, students may need to explore various architectural projects by visiting them on the map, and then they could upload their assignments (and even photos of their own) to the map where the rest of the group can see them.
Currently, Berlin is the featured city and the one that has the most complete content. There is some content for Los Angeles, and there are plans to add New York, Chicago, Paris, and Beijing. Check it out at http://www.hypercities.com/. It’s still a work in progress, so some of the features may not be active yet.