low cost VR/AR systems
guides to making imersive projection systems on the cheap
an Unreal Tournament mod. to enable projection in a cave like system
http://www2.sis.pitt.edu/~jacobson/ut/CaveUT.html
some homebrew VR links
http://www.phoenixgarage.org/homevr/index.html
Syzygy toolkit for VR on pc clusters
http://www.isl.uiuc.edu/ClusteredVR/ClusteredVR.htm
also
Game Engines