I haven't written anything about Edusim on this blog - Something about it screams Beta software more than most but things are definitely changing.
Edusim is a 3D Networked environment that you can place learning objects into.
They are starting to put google sketchup items into the Edusim environment...
Now this is getting good. Now you can create 3D learning environments populated with a choice of thousands of 3D models for free. Awesome.