People dreamed of flight like birds since the most ancient timesвЂ¦ And here in the beginning of 20 century the man has flew off, a little not how dreamed, inside вЂњiron birdsвЂќ, a.k.a. airplanes.
Around two centuries (may be more), people dreams of the time machine. The end of 20 century has gave hope for realization and this dream вЂ” the virtual cyber-worlds.
At present time, a fight between Google and Microsoft for virtual model of the Earth is emerging. Yes, now all is focused on information search about objects on surface in the instant moment of time. But having the virtual Earth and historical archives indexed (yes, still having to dig and dig here), it is possible to reconstruct in detail some fragments of a surface of the Earth in the past, for example famous battlefields, or the propagation of a tsunami wave to Asia in December 2004, or the sole voyage of "Titanic", etc. Basically it is possible "to turn off" back all history of the Earth, till the moment of origin of the Sun.
OFF-TOPIC: Also using a model of virtual Earth, it possible to make a "real" Civilization game online over "real" Earth.