MirrorWorlds by DavidGelernter, ArtificialIntelligence researcher. A predictive book about the next 20 years in the net.future.
"A Mirror World is some huge institution's moving, true-to- life mirror image trapped inside a computer--where you can see and grasp it whole."
Basically, he believes reality will be reflected online and online will be reflected in the RealWorld. VirtualReality and RealVirtuality.