A few of us, who remember the old three-channel plus UHF days when turning the TV on meant waiting a minute or two for the tubes to warm up, are still around.

Gone are those days. Hit a button on the remote control and the big screen fires up in a matter of seconds.

Back in the tube days, though, when the TV was left off for an extended period, it would cool to room temperature.

That's not necessarily the case now. Then there's the array of ancillary TV related equipment, including, but not limited to, cable boxes and disk players. Even after lights out, these devices still glow green, blue and red, and they stay as warm as puppies, day in and day out, so they can be ready for instant activation.

Even those of us who remember the old days of TVs being truly off when you turned them off don't give a second thought about the warm wonders of modern communications technology; but some people do, to the potential financial benefit of the rest of us.

The volunteer group that runs the Eden Mill Nature Center on Deer Creek in Pylesville is tuned into the realities of modern residential electrical use and has made it possible for the rest of us to get a handle on what it's costing.

The Nature Center's board - at a cost of about $1,000 - donated devices called Kill A Watt EZ Power Meters to local library branches, making it possible for library patrons to use the technology to determine what it costs to keep a TV, or a computer or a video game plugged in and at the ready for instant activation.

Last week, when the devices were shown off at an unveiling event, they were used to compare the cost of running an old style 75 watt incandescent bulb to that of running a modern CFL or compact fluorescent bulb of the same brightness for a half hour.

Subsequent calculations for a year's worth of light, based on power usage recorded by the Kill A Watt devices, revealed that the old style bulb cost $88.60 to keep on, while the CFL bulb's cost was $19.60.

Similarly, it would be possible to plug a TV and its accessories (through a power strip) and calculate how much it cost to keep them plugged in but not turned on.

The devices donated by Eden Mill don't save any electricity or money on their own, but for those who are interested, they provide a way of determining the costs of the convenience of instant access to TV (or computer or whatever).

After that, individual decisions can be made about whether to switch off the power strip too, or if it's worth the extra money to just leave the devices glowing through the night.