I just watched a show on TV that showcased [VirtuSphere](http://www.virtusphere.com/).
> The VirtuSphere platform consists of a large hollow sphere that sits on top of a base and allows the sphere to rotate 360 degrees. Wearing a wireless, head-mounted display, users can step inside the sphere to fully interact in immersive virtual environments. The VirtuSphere enables 6 degrees of freedom â€“ one can move in any direction; walk, jump, roll, crawl, run over virtually unlimited distances without encountering real-world physical obstacles.
Imagine [Ghost Recon](http://www.ghostrecon.net/) in that?!!!