The best list of virtual world links.

I just came across an excellent list of virtual world links. It's at http://sleducation.wikispaces.com/virtualworlds .

Joining all the virtual worlds listed there, even just the free ones, and participating a bit in each world, reading and posting in each world's forum, studying a bit about the technology involved in each, etc., would take a fair bit of time and should transform a virtual world novice into someone with a fair grasp of the virtual world scene.