VingCard's sister company Timelox AB in Landskrona, Sweden, has installed smart card technology in hotels such as The Venetian and Bellagio in Las Vegas and some Starwood properties, and VingCard plans to introduce its own RFID cards in 2006, Lane says. In this system the door lock establishes an infrared connection to the wall thermostat and tunnels through the energy management system to communicate with the lock management system at the front desk. The system has several advantages -- it can tell if the door is ajar or is being jimmied, for example. It includes motion sensors to determine whether anyone is in the room and can adjust the climate control system to save energy if it's unoccupied.

It also allows the front desk to remotely control or reprogram the door locks. If you checked into a room on, say, the 18th floor and something was wrong, you could just call the front desk and the staff there could redirect you to room that's ready a few doors down. Front desk personnel could reconfigure the locks of both rooms so the one on the door of the new room accepts your card and the one on the old one doesn't. No elevator ride back down to the front desk would be necessary.

Such systems aren't for every property, says Lane. First of all, they're not cheaper than traditional electronic locks with magnetic key cards. They're also more complicated and harder to maintain. "They are great for a big property, but what happens at the Best Western?" Lane says. "It's not out there [because] it's expensive, hard to support."

Such systems also present potential liability issues because they provide bidirectional communication between the front desk the room. The system knows when a door is being pried open or has been left ajar. "You'd better have someone monitoring because you've set up a liability," Lane says.

For hotels that can afford it, the return on investment in energy savings is there. At most hotels, however, the rule is, "Keep it simple." The economical, workhorse magnetic card key is likely to remain the room security system of choice at most hotels for the foreseeable future.