Human "cyborgs" move from science fiction fantasy to reality as new technology lets some employees volunteer to let an implanted microchip serve as their workplace ID badge. Instead of showing or swiping a photo card with a magnetic strip to access employee-only areas, users can hold a hand near a chip reader to verify their identity and security level. Each tiny hand implant, about the sizer of a rice grain, uses something called near-field communication technology (NFC) that's also in key cards to open hotel room doors and that’s implanted in pets to identify them if lost. When activated by a reader a few inches away, a small amount of data flows between the two devices via electromagnetic waves.

A handful of companies are the first to offer chip implants to workers, which lets them open locked doors with a hand wave. The invisible IDs also can authorize computer access, printer use or charge items in a company cafeteria. "The biggest benefit, I think, is convenience," says Patrick Mesterton, co-founder and chief executive of Epicenter, a Swedish company where about 150 workers have the microchips. "It basically replaces . . . credit cards or keys." The first U.S. employer giving it a try is Three Square Market of River Falls, Wis., where any of the marketing firm’s 85 employees can begin volunteering this week. If employees later change their minds, they can have the implant removed.

As with many new technologies, security and privacy concerns arise. Each touch leaves a digital footprint. Data generated can show how often employees come to work, what they do, what they buy and how long their breaks last. Unlike company swipe cards or smartphones, which can generate the same data, people can't separate themselves from chips under the skin in the fleshy area next to the thumb.

Volunteer says: "I want to be part of the future." -- Sandra Haglof, 25, worker in Sweden

Tech editor says: "This is serious stuff. We're talking about a nonstop potential connection to my body and I can't turn it off, I can’t put it away, it's in me. That’s a big problem." -- Ian Sherr, executive editor at CNET, a consumer technology website

U.S. user says: "Eventually, this technology will become standardized -- allowing you to use this as your passport, public transit, all purchasing opportunities." -- Todd Westby, chief executive of Three Square Market in Wisconsin