Sometimes it's good to go to a session just because you think you might enjoy it, rather than you might learn something from it. That's why I've just been to one on teaching chemistry and microbiology in a virtual lab in Second Life. The University of Aalto in Finland have created LabLife3D, a virtual building with clean rooms, laboratories and a lobby area where students can discuss things.
Students are taught to use equipment before entering the real lab, and have to pass certain tasks relating to lab safety, especially for the clean room. They can also perform experiments, including being able to fast forward time for cell cultures etc. It enables larger classes to be taught more cheaply, and the students to learn at their own pace and in their own time. The students rate it positively. Downsides are that it requires a lot of specialist skills to build the virtual reality, and currently mistakes or accidents in the experiments have no consequences. This is currently being developed.
A good presentation, delivered entirely from Second Life, with some current students in Finland taking part through their avatars. My main criticism is that the Second Life interface seems so clunky, especially when compared to modern gaming environments. Not at all intuitive.