Face: The Final Frontier

Google founder Sergey Brin (L) and designer Diane von Furstenberg sit and watch the rehearsal for her Spring/Summer 2013 collection show during New York Fashion Week September 9, 2012. The show was used as a launching event for Google's new product "Glass by Google". REUTERS/Carlo Allegri

Wearable gadgets like smart watches and Google Glass can seem like a fad that has all the durability of CB radios or Duran Duran, but they're important early signs of a new era of technology that will drive investment and innovation for years.

Tech companies are pushing out waves of wearable technology products - all of them clumsy and none of them yet really catching on. Samsung is feverishly hawking its Galaxy Gear smart watch, and Google, Apple, Qualcomm, and others are expected to come out with competing versions. Google Glass gets lots of gee-whiz attention, and every other day, someone new introduces a fitness tracker, a GPS kid-monitoring bracelet, or - yeah, seriously - interactive underwear.

These are all part of a powerful trend: Over the past 40 years, digital technology has consistently moved from far away to close to us.

Go back long enough, and computers the size of Buicks stayed in the back rooms of big companies. Most people never touched them. By the late 1970s, technology started moving to office desks - first as terminals connected to those hidden computers, and then as early personal computers.

The next stage: We wanted digital technology in our homes, so we bought desktop PCs. A "portable" computer in the mid-1980s, like the first Compaq, was the size of a carry-on suitcase and about as easy to lug as John Goodman. But by the 1990s, laptops got better and smaller, for the first time liberating digital technology from a place and attaching it more to a person.

Now we want our technology with us all the time. This era of the smartphone and tablet began in earnest with the iPhone in 2007. The "with us" era is accelerating even now: IBM announced Thursday that it's making its powerful Watson computing -- the technology that beat humans on Jeopardy! -- available in the cloud, so it can be accessed by consumers on a smart device. In technology's inexorable march from far away to close to us, and now with us, there are only three places left for it to go: on us, all around us, and then in us.

"Wearable is the next paradigm shift," says Philippe Kahn, who invented the camera phone and today is developing innards for wearable tech. "We are going to see a lot of innovation in wearable in the next seven years, by 2020."

Hard to know which products will catch on. Glasses are an obvious way to wear a screen, but most people don't want to look like a tech geek. The masses might get interested if Google Glass can be invisibly built into hot-looking designer frames. A start-up called Telepathy is developing a slim arm that holds a microprojector that shoots images back to your eye. Another concept is to build a device with a tiny projector that suspends text or images out in front of you, like a heads-up display.

Watches and bracelets put tiny screens and sensors on your wrist. Start-up Hexoskin is developing fitness clothing embedded with technology that can monitor your body. Clothes or jewelry might let you feel data, buzzing on a certain part of your body for a text message, another part for a call from your mother - a kind of tactile ringtone. The Hasso Plattner Institute in Germany has been messing with interfaces that use parts of the body, like letting you dial a number by touching different fingers. (Combine this with interactive underwear, and it might have something.)

The technology will become almost unnoticeable - always there, a part of you. It won't be obvious, and it definitely won't try to be fashionable. It will instead become seamlessly integrated into the stuff you wear and carry, no more obtrusive than a pair of sunglasses.

Then when you are walking down the street, you can pay attention to the real world. Messages and data will come to you at appropriate moments - rather than your having to pull out a screen and look for them. That will allow you to keep your eyes up and away from screens, making a stroll on city sidewalks a lot less like slam dancing through a 1980s Ramones concert.

Just as having technology with us begat unexpected applications (Uber, Shazam, Evernote), having it on us will do the same. Because the devices will be able to track our bodies and movements, we already know the new era will have implications for health care and fitness.

And next, technology will surround us. Technology-enabled rooms will recognize who walks in and turn every surface into that person's "screen." Messages, data, video, and simulations will be all around, movable with a gesture.

Will technology really end up inside us? A lot of scientists say so. Forty years back, it was preposterous to think that so many people would get metal replacement knees once their real ones failed. A couple of decades from now, I'm hoping for a replacement memory when mine goes.