It's hard to figure out how to save energy in your home if you don't know how much you're using and where. That's why those who are serious about saving money or electricity are turning to electricity meters.

Formerly the province of serious electronics geeks with $1,200 to blow on a big, elaborate meter, pocket-sized electricity meters are now becoming popular with the masses.

Daniel Dern at ComputerWorld took a close look at some of the products out there, and recommends a "plug load meter" that measure the output of an individual appliance. It tracks the device over a period of time so you get high and low output numbers, then calculates how much energy it uses and how much money that costs over a typical month or year.

According to Dern, the $60 Kill A Watt EZ is a good choice for the average consumer who wants a basic electricity meter. The somewhat pricier $131 Watts up? Pro is good for folks who really dig into the data on their computer and the $249 Brultech ECM-1220 PKG will work for those who want to be able to measure the power from appliances that don't have a plug, like dishwashers.

Most people aren't going for the $250 device because they figure that's more money than they'd save. I also found that Newegg sells the P3 Kill A Watt for $18.

Of course once you figure out how much power you're using, then you have to come up with a plan to cut usage by using appliances less, unplugging appliances when they're off or replacing energy hogs.

Cyberguys has the biggest selection of "smart" surge protectors I've seen; they have a "master" outlet for your computer and "slave" outlets for your computer accessories. When you turn off the computer you turn off everything else. The meter may lead you to unplug devices that aren't on but are still sucking energy. That's what's known as "vampire power," referring to appliances such as digital clocks and remote controls sensors. People who know about such things disagree on how much these extras actually waste, some say 5%; others go as high as 25% . The only way you'll know is if you join the masses and get yourself an electricity meter.