Editor's note: Pete Cashmore is founder and CEO of Mashable, a popular blog about social media. He is writing a weekly column about social networking and tech for CNN.com.
London, England (CNN) -- A U.K. firm is set to launch a camera to capture every moment of a person's life. While you may reel at the privacy implications, I'd wager that the high price of not capturing and sharing every moment of our lives will soon dwarf the cost to our privacy.
The SenseCam, worn on a cord around the neck, will retail for $820 and capture an image every 30 seconds. Originally developed by Microsoft Research in Cambridge, England, the technology has been licensed to Oxford-based Vicon, which will produce a version for Alzheimer's and dementia researchers by the year's end and a consumer version in 2010.
It's easy to see the associated risks of a life-logging device. From stalkers to identity theft, recording such information (and to unlock its true value, posting it online) makes us vulnerable to all manner of bad actors.
But what about the cost of not sharing? In the online realm, that might mean you simply don't exist.
Privacy is dead, and social media hold the smoking gun.
Photo-sharing site Flickr made a brave decision in its early development: By default, photos would be public. Though ambitious at the time, the choice now seems obvious. What value do photos have when they're not shared?
Twitter followed suit: Its private accounts are rare, meaning Twitter's fire-hose of updates is becoming an invaluable stream of the world's consciousness (incidentally, this month saw that stream licensed to both Microsoft and Google to bolster their search efforts).
Even Facebook, which once held fast to its model of private sharing among close friends, is pushing an "everyone" button that makes your updates public.
Unknown and unemployed
The value of a life led in public is most obvious to those seeking employment. Working in media, I frequently find myself talking to journalists who now possess a distribution channel entirely separate from their publication.
With thousands of Twitter followers and hundreds of Facebook friends, these writers are building large audiences for their personal brands that make them a valuable asset to employers.
As he tweets out his latest story to his 1.1 million Twitter followers, does David Pogue need The New York Times, or does The New York Times need David Pogue? And what becomes of the newly unemployed journalist who doesn't set up a Twitter account like Pogue, who has posted more than 2,000 tweets on technology, fatherhood and other topics?
Without industry connections or a valuable audience for your work, you aren't even on the radar.
Unemployment is just an extreme example of the cost of not sharing in professional life, of course. The "who you know" mantra holds true throughout the world of work, and the more content we share, the more connections and opportunities open up.
Location-based services lead the way
New York-based Foursquare is being heralded as the "next Twitter" by the team at Mashable, early adopter Robert Scoble and numerous thought leaders in the tech space. Posting an update from your phone every time you "check in" to a restaurant or bar might be seen as an invite to have your house robbed ... but what of the hundreds of missed connections when you choose not to share? In this connected era, a private life is a lonely one.
Foursquare is far from alone, however: From Twitter's upcoming location-based features to Google Latitude, not to mention the fact that most modern smartphones ship with GPS, sharing your location looks set to become the default, too.
You can't improve what you don't measure
This month also saw the first shipments of the Fitbit: This clip-on pedometer is worn day and night, logging your exercise and sleep patterns and sending the data wirelessly to the Fitbit Web site whenever you're near the base station. Do I need to mention that this data is then shared with friends and family?
The benefits here are obvious: Logging all your physical activity online gives incentives to improve and accurate measurements of your progress. Roping in friends and family makes this a shared goal. You're not alone in your fitness regime.
Don't want to share? Scared what others might think? Ask yourself whether the opportunity cost is really a price worth paying.
In the attention economy, privacy is obscurity
We're living at a time when attention is the new currency: With hundreds of TV channels, billions of Web sites, podcasts, radio shows, music downloads and social networking, our attention is more fragmented than ever before.
Those who insert themselves into as many channels as possible look set to capture the most value. They'll be the richest, the most successful, the most connected, capable and influential among us. We're all publishers now, and the more we publish, the more valuable connections we'll make.
Twitter, Facebook, Flickr, Foursquare, Fitbit and the SenseCam give us a simple choice: participate or fade into a lonely obscurity.