Here is a video of a 3D virtual office space created in SecondLife:
You can see a demonstration of an earlier prototype of this space here.
Here is a video of a 3D control room space created for one of our customers:
Here is a video of an earlier mixed-reality teaching space created in Wonderland 0.4:
Other videos: EUNIS 2008 keynote: Using Project Wonderland to develop and deploy virtual 3-D collaborative environments for teaching and learning, by Michael Gardner (video)