It's a memory aid! A robotic assistant! An epidemic detector! An all-seeing, ultra-intrusive spying program!

The Pentagon is about to embark on a stunningly ambitious research project designed to gather every conceivable bit of information about a person's life, index it and make it searchable.

What national security experts and civil libertarians want to know is, why the hell would theDefense Department want to do such a thing?

The embryonic LifeLog program would take every e-mail you've sent or received, every picture you've taken, every web page you've surfed, every phone call you've had, every TV show you've watched, every magazine you've read, and dump it into a giant database.

All of this -- and more -- would be combined with a GPS transmitter, to keep tabs on where you're going; audio-visual sensors, to capture all that you see or say; and biomedical monitors, to keep track of your health.

This gigantic amalgamation of personal information could then be used to "trace the 'threads' of an individual's life," to see exactly how a relationship or events developed, according to a briefing from the Defense Advanced Projects Research Agency, LifeLog's sponsor.

Someone with access to the database could "retrieve a specific thread of past transactions, or recall an experience from a few seconds ago or from many years earlier … by using a search-engine interface."

On the surface, the project seems like the latest in a long line of DARPA's "blue sky" research efforts, most of which never make it out of the lab. But Steven Aftergood, a defense analyst with the Federation of American Scientists, says he is worried.

With its controversial Total Information Awareness database project, DARPA already is planning on tracking all of an individual's "transactional data" -- like what we buy and who gets our e-mail.

Aftergood said he believes LifeLog could go far beyond that, adding physical information (like how we feel) and media data (like what we read) to this transactional data.

"LifeLog has the potential to become something like 'TIA cubed,'" he said.

My Wired News article has details on the LifeLog program.

THERE'S MORE: The idea of committing everything in your life to a machine is nearly sixty years old. In 1945, Vannevar Bush -- who headed the White House's Office of Scientific Research and Development during World War II -- published a landmark Atlantic Monthly article, "As We May Think." In it, he describes a "memex" -- a "device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility."

Minicomputer visionary Gordon Bell, now working at Microsoft, sees his "MyLifeBits" project as a fulfillment of Bush's vision.

There are other commercial and academic efforts to weave a life into followable threads, including parallel processing prophet David Gelernter's "Scopeware" and "Haystack," from MIT's David Karger.

AND MORE: LifeLog may eventually dwarf Total Information Awareness, DARPA's ultra-invasive database effort. But "TIA" could wind up being pretty damn large on its own, with 50 times more data than the Library of Congress, according to the Associated Press.

AND MORE: Lovers of civil liberties, you now have nothing to fear. Henceforth, the creepy "Total Information Awareness" program will be known as "Terrorism Information Awareness."

Feel better?

AND MORE: DARPA's report to Congress on TIA is online here.