I saw this posted internally http://www.scottmcleod.org/didyouknow.wmv and it reminded me of a talk Ray Kurzweil he once gave giving timelines for many things.  It is worth having a poke around his site - http://www.kurzweilai.net/index.html?flash=1 and also at some of his predictions - http://www.bbc.co.uk/worldservice/business/features/future_perfect/trans6.shtml.

By 2009, we won't be carrying around notebook computers or even palmtops you won't see the computers. The visual display's will be written directly onto our retinas from eye glasses and contact lenses so we'll either see a virtual display hovering in air or, even more compellingly, the visual display can overtake our whole visual field of view and create, basically, visual virtual reality.

ttfn

David