I'm a huge fan of science fiction. That's partly because I'm an optimist -- I want to believe that Star Trek could happen. But I'm also painfully aware of sci-fi's dark side, which almost always has to do with machines and humans mixing in ways unnatural. (Darth Vader, anyone?)

So color me conflicted at yesterday's news that Cincinnati security firm CityWatcher.Com had two of its security guards implanted with radio frequency identification devices, otherwise known as RFID. These plastic "tags," as they have become known, broadcast data using radio signals, making it possible to track almost anything wirelessly -- from cargo to playing cards to, apparently, human beings.

Chilling, you say? I agree, but I'm also forced to admit that the idea makes eminent sense. We've been personalizing security for just short of forever now. Fingerprinting, retinal scans, voice identification. Security systems simply want to make sure you are who you say you are. RFID would make that process even more seamless.

There's also health care. The chip maker behind the implants, VeriChip, which literally calls its technology "RFID for people," says its technology is FDA-approved and could be highly useful for patients who have trouble communicating on their own.

Hospitals seem to agree. VeriChip is establishing a network of facilities with readers capable of reading data from its implants. According to the Chicago Tribune, Hackensack University Medical Center in Hackensack, N.J., already has the equipment up and running. More than 65 other hospitals have requested it.

Yet even with all that goodness, I can't get 1984 author George Orwell out of my head. He's got to be saying, "I told you so," right? The privacy implications are just too huge. Who's going to make sure the tags are programmed to track only what should be tracked? What's to prevent anyone with a reader from stalking me if I have an implant? You say this scenario is nothing more than my rampant paranoia at work?

In the meantime, RFID remains big business. Indeed, Research & Markets, in a June 2005 report, estimated that the RFID industry would grow from $1.95 billion in 2005 to $26.9 billion in 2015. That's better than 30% annual growth. Wow. The potential winners include Zebra Technologies (NASDAQ:ZBRA), Printronix (NASDAQ:PTNX), and, naturally, VeriChip, which in December filed an S-1 stating its intent to offer shares to the public. It plans to list on the Nasdaq with the ticker "CHIP."

So, George, step aside. It's man and machine, hand in wallet -- until, that is, the long shadow of the Dark Side sets in. Hey, who's that behind me? (Cue heavy Vader-esque breathing.)

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Fool contributor Tim Beyers thinks Darth Vader is da bomb, but he'd say anything to keep from getting skewered by a light saber. Tim didn't own stock in any of the companies mentioned in this story at the time of publication. You can find out what's in his portfolio by checking Tim's Fool profile . The Motley Fool has an ironclad disclosure policy .