Smeet lets you create 3D rooms where your avatar can chat and interact with other avators. You have register, but no download is necessary.
A tool like this one might be useful in an education setting. For example, if students from our International Sister Classes Project were going to communicate in real time, Smeet might be a bit more engaging than some of the other applications on The Best Online Tools For Real-Time Collaboration list.
I’ve asked Smeet if it is possible for teachers to create private rooms only available to their students. Their response has been “yes,” but they didn’t explain how to do it, and I can’t figure out how to incorporate the privacy option. Obviously, it would only be useful if that feature could be implemented.