You're stretched out on the sand in Cancun and suddenly realize that you forgot to arm your home's security system. You also neglected to adjust the thermostat to save energy while no one's home. What's worse, you can't remember whether or not you turned off the iron.

No problem. You just stroll over to the pay phone by the beach, dial up your house and tell it you're on vacation. It'll know to change the thermostat, arm the alarm and shut off power to appliances. It may sound like the future, but it's the present for a small but growing number of Hoosiers who live in Smart Houses.

"Smart House" is a trade name for the technology developed several years ago by the National Association of Home Builders' research center. "Builders were saying that nothing much had changed in the industry since we started putting air conditioning in houses in the 1940s," recalls Larry Goldman, a pioneer of the Smart House concept and now product manager for Molex Inc., which makes Smart House components.

Every switch, electrical outlet and fixture in a Smart House is connected directly to a computerized control unit. It can also connect with the home's heating, cooling and security systems, entertainment and communications equipment.

A television upstairs can receive its programming from a VCR downstairs through Smart House wiring. A new phone line for the kids can be routed directly to their rooms, then redirected to the home office when they go off to college, all without tearing up walls. A visitor at the front door can be instantly pictured in the corner of a TV screen when the doorbell rings, and the resident can communicate with the visitor by picking up the phone.

Also, residents can control various functions of the home through different preprogrammed modes, which can be selected from a control panel, any wall switch or even through the phone. Choose the "asleep" mode, for example, and the lights go out, the alarm goes on and the thermostat is adjusted. Push the "awake" button and lights slowly fade on, the thermostat is readjusted and the coffee begins to brew.

What does a Smart House cost? That depends on the size of the house and the options chosen, says Roger Pope, president of Carmel-based Smart House supplier Electronic Integrated Systems. In general, he says, it can double the electrical installation contract when a house is being built, which he adds is the best time to install Smart House technology.

Last summer, Indiana Gas participated in the construction of the state's first natural-gas Smart House, a home in Plainfield. Mike Hanley, marketing communications manager for Indiana Gas, says the project was a logical one for the gas company to participate in.

"It provides for added safety for the products, both natural gas and electrical, and it provides an opportunity to use more natural-gas products in a more integrated way," he says. Flexible gas piping makes it easy to install gas appliances of all kinds, and even move them around.

The Smart House can automatically light the gas fireplace when asked to do so, he says. The gas water heater can be controlled for added efficiency. And a Smart House natural-gas outlet allows easy connection of the outdoor gas grill, meaning it can be put away when not in use.

Will we all live in Smart Houses someday? "As the price comes down, more people will do it," Pope says. "And if anyone ever lives in a Smart House, they'll never live in anything else."