The best example of INTERACTIVE, free, open, high quality teaching and learning which I currently know of in Second Life is the Goethe Institute's 1 lesson a week, and 6 days-a-week conversation opportunities - worlduniversity.wikia.com/wiki/Courses#Language_Learning. Know of other free, open teaching and learning opportunities? Please add them! Invitation to teach, learn and add to World Univ & School.
I'm adding a "Virtual World" section to the World University & School's Subject Template to make interactive teaching & learning directly accessible:
Add a subject which interests you to the open, free, Wikipedia-like World University & School, with a virtual world teaching and learning possibility.
(http://scott-macleod.blogspot.com/2010/01/welwitschia-language-learning-at-world.html - January 21, 2010)