Re: Total Recall?
Part of the plot of the book by Arthur C. Clarke and Stephen Baxter, _The Light of Other Days_ concerns a media mogul who develops this capability, the ultimate in virtual reality. The main plot of the story is about devices that can view anyone, anywhere, at any time.
In regards to the question of how could we know the difference between the illusion and the reality, how do we know we're not already in the illusion?
(cue the Twilight Zone music.)
;-)
Bob Clark