Before the advent of the written word, the story goes, humans had to either store all their memories in their own heads, or by oral tradition passed down through designated members of their tribes. With trade came notation of facts and figures, and later alphabets, books and libraries. With them came the modern brain, which treats recorded knowledge as an extension of itself.

Throughout these developments, previous generations have grumbled that each new advance leaves us worse off — take this month’s issue of the Atlantic, which includes a feature story titled “Is Google Making Us Stupid?” by Nicholas Carr. Yet Google’s search-and-retrieve functions are only the tip of the Internet iceberg, when it comes to memory. A whole new generation of efforts to move our memories online is in the works, and may represent one of the biggest upcoming movements in computing.

Pensieve, an IBM technology, is the latest project to unveil itself. The idea, being able to snap pictures of business cards and people with your cell phone for later retrieval, sounds almost identical to Evernote, a company I reported on a month ago when it came out of private beta. That doesn’t mean IBM is copying; rather, that IBM is taking the most obvious tack first. Business cards (as well as receipts and other short, printed matter) are easy for image recognition software to read.

The problem right now is that the low-hanging fruit is fairly limited. Recording is easy — so easy that a Microsoft researcher has been doing it for nine years, saving photos, videos, web pages, and nearly everything else he interacts with.

Each of those capabilities is now duplicated for regular people. “Life casting” became a minor fad with last year, and more recently Qik’s had its public launch. Other companies like Kyte also offering video and picture feeds from your mobile phone, all of which can potential be saved. Emails have always been possible to save, although companies like Zimbra and Xobni have since added much more functionality, while Xoopit helps search through mail. For web pages, there are bookmarkers like Delicious, and upcoming services like Twine, whose private beta I’ve started using to save my web ramblings, although the service itself still needs plenty of work.

However, there’s still a lot missing. First, you need an integrated storage spot for all this material. Hard drives die, photo sharing services go down, email accounts are hacked. It’s likely that in the future web companies will exist that offer ironclad storage for all your data — meaning the complete, unedited record of your life. Storage services abound right now, but users will want something special for storing their lives.

Almost as important are editing services to narrow all the incoming data to points, which can be disseminated across Facebook feeds, weblogs and other public forums. If you really did record your whole day today, you’d have to spend a lot of time searching out the moments that mattered and tagging or annotating them for immediate use or later retrieval. The more automation exists, the more people will record parts of their lives.

Search and editing, in fact, are choke points that may stunt the growth of a memory industry. But then, there are trends that suggest otherwise. Image recognition, driven by advertising uses, is advancing rapidly under the care of companies like Blinkx and Viewdle. Voice recognition has stalled researchers for years, but companies like SoliCall and VoiceBox may yet offer a working solution.

Once software can recognize pictures, video and audio in addition to text, the work passes on to the growing ranks of semantic startups. Twine itself isn’t just a storage point for web pages; it’s attempting to add structure through automatic, intelligent tagging so that when you’re trying to find something you’ve saved, it’s easy. (A similar effort not yet out of stealth is called Qitera.)

Such startups will represent the first set of technologies that can truly help establish external stores of memory. Simulating short-term memory early startups like ReQall and Jott, both now available on the iPhone, already help with day-to-day reminders.

Our long-term memories are the tougher nut to crack, but there’s a wealth of opportunity in automated journals, work streams and research logs, not to mention data mining services that can help us manage our time better (RescueTime is an early example). And a true integrated service may be closer than it seems; take a look at Numenta, which is working on a “hierarchical temporal memory system (HTM) patterned after the human neocortex.”

And when all these things exist, what will happen to our memories? As the Atlantic article suggests, we may find that the net effect is to “scatter our attention and diffuse our concentration,” — or, as it argues in another part, we could spur a “golden age of intellectual discovery and universal wisdom.” The result may well depend on the quality of the efforts.