Basically, 3D cameras would allow the virtual world software to interpret how users are moving in the real-world and to translate that movement into the software. That could mean, then, that if the user raises his or her hand, so too does their avatar.

Basically, 3D cameras would allow the virtual world software to interpret how users are moving in the real-world and to translate that movement into the software. That could mean, then, that if the user raises his or her hand, so too does their avatar.
Mitch Kapor: 3D cameras will make virtual worlds easier to use