Contrary to the long-standing sci-fi trope, future humans will not live out their existence in virtual-reality cocoons, floating in tanks as computers construct a little synthetic bubble around them. Rather, we'll virtualize our entire environment, so that the entire world around us is a synthetic place. The technology to do this is most of the way there; it's only a couple cranks of Moore's Law away.
Google's proposal for magic glasses provide the display mechanism:
But why stop with a translucent overlay of information? Why not create a full-motion, three-dimensional world on the fly?
I imagine a future in which you get up in the morning, slip on your magic glasses and your gray jumpsuit with the little motion-capture balls, and head out to face the day. As you encounter other people, the cameras in your glasses read the position and movement of the motion-capture balls on their suits and construct an armature describing their motion. Then the computer in your glasses receives an appearance file from the other person's magic-glasses computer, wraps that body around the motion-capture armature, and presents the other person to you exactly as he/she wishes to be seen. At the same time, of course, the other person's camera is capturing your motion, receiving your preferred appearance from your magic-glasses computer, and displaying to the other person the you that you'd like the world to see.
That "you," of course, would be "you, perfected." At the very least, "perfected" as in Jesse Rosten's "Fotoshop by Adobé" commercial spoof:
As the model says, why eat right and exercise when you can just look like you do? After all, every time you go out in public, you're inflicting your appearance on everyone who's forced to look in your direction. Don't you have a civic duty to look like one of the Beautiful People?
But why stop with a human being? Feeling a little post-Avatar depression? Just tell your magic glasses to show you to the world as a Na'vi (the procedure to make yourself into one via Photoshop is already out there). Or maybe you'd rather be a Klingon, or a Minbari, or an Angel. There's no limit to who, or what, you could be--and there's no reason to have just one! Change your appearance on the fly, depending on your mood, or perhaps upon whom you're about to meet (for that next business meeting, perhaps you'd like to try the Incredible Hulk).
And, of course, it's not limited to just your own appearance. The potential for on-the-cheap urban renewal should be obvious. With a virtualized environment, the city government doesn't have to clean up the dismal streets or dilapidates subways; all they have to do is install a transmitter that tells your magic glasses what the streets and subways are supposed to look like, and the glasses will do the rest! Finally, we can have a City Beautiful and low taxes!
Once things get going, you'll want to edit the reality around you. Stuck in a drab Midwestern corn town when you've always wanted to live in the mountains? No problem, just plug in the mountain landscape background module. Think that downtown office building is an architectural abomination? Edit it out, or replace it with the building you think should have been constructed on the site.
If I weren't something like three years behind schedule on my second novel, I'd write a story about virtualizing the world. Maybe one of those "surprise ending" stories in which the technology fails abruptly and people have to deal with real reality. But I figure, by the time I've finished the book I'm working on and written that story, it won't be fiction anymore. We already have the technology to virtualize the entire world around us; it's just a matter of making it small enough and cheap enough to deploy on a large scale. And in the computer industry, by the time you've figured out how to do something, you're just a matter of months from having it done small and cheap.