What is the definition of a virtual world? Well, let's see what the Wiki says:
"A virtual world is a computer-based simulated environment intended for its users to inhabit and interact via avatars. These avatars are usually depicted as textual, two-dimensional, or three-dimensional graphical representations, although other forms are possible (auditory and touch sensations for example)."
By that definition, is RockBand a virtual world? Technically I think it is and if that's the case then it might be the world's biggest virtual world!
I feel an article coming on...