Belkin’s Conserve Insight is one of those products, as well as Tenrehte’s PicoWatt. But the simplest and most powerful smart outlet is the Modlet by ThinkEco.

The device is a two outlet power strip that plays a dual role as a timer and power consumption meter. The device uses a form of wireless networking (802.15.4, or Zigbee) to connect to a USB dongle that is plugged into your computer, and will send information including power consumption and cost and timer information to and from the device.

ThinkEco claims that using the device can save you 10 to 20 percent on electric bills by monitoring power usage, and will even recommend when the device should be turned off to save electricity. The company pointed out to me that the biggest wastes of electricity are the ones we don’t know about–those involving products that are on standby but still drawing a good deal of power.

The true value of the device, however, is in the Web application that drives the Modlet. A real-time graph shows the power usage (broken down by individual power outlet) of all used Modlets and provides remote control of plugged-in appliances from any computer with a browser, and even shows the cost if you have provided cost per kilowatt hour information.

Modlet’s Web interface can also make suggestions on when to schedule the power to be cut to the device. All in all, it’s aimed at giving users more control over their power consumption before they find out about it on their next electric bill.

I was thoroughly impressed with the product, and its price–expected to be around $40 when it launches this fall–isnt prohibitive. ThinkEco also said that a traditional power strip model is planned. I’m definitely interested in that: I’d love to know how much my home office is really costing me in terms of electric consumption, and saving money is never a bad thing.

At first blush, Hohm sounds suspiciously similar to Google PowerMeter, a service Google launched a few months ago to help consumers monitor their power consumption and figure out ways to cut usage and costs. But while PowerMeter requires a special smart meter or other power-monitoring equipment in the home and is  the result of collaboration between Google and a few utilities, Hohm is designed to be immediately useful to anybody with an interest in using it. Microsoft does plan to collect data from smart meters (as well as smart plugs, which plug into the wall and then monitor the devices you plug into them). And the company is planning to work with utilities to let consumers transfer information about their power usage for detailed analysis.(So far, it has only four utility partners, in Seattle, Sacramento, and the midwest, but it says it hopes to have a bunch more on board by the end of the year.)

But all of this is optional–Hohm will also provide advice if all it knows about you is your zip code, the age and size of your house, the type of heating you have, and a few other facts. Or, if you’re really serious about going green, you can fill out a 200-item (!) questionnaire to get the most sophisticated advice possible on how to reduce your power usage.  The advice it gives is the sort of stuff you’d expect, from installing compact fluorescent lightbulbs to having your home’s ducts sealed, and the service includes a planning feature that lets you set deadlines for yourself for accomplishing each task. (Microsoft says it plans to make money eventually by selling advertising to contractors and others who might help you with more elaborate energy-saving steps.)

I was one of several journalists who Microsoft briefed on Hohm yesterday;  the service looked slick. useful, and ambitious in the company’s canned demo. But the real test will be trying it and discovering whether its analysis and advice does indeed help slash power consumption. If nothing else, I like the idea of a service of this sort that isn’t dependent on any high tech within the home. (My house is 57 years old and a shockingly high percentage of its infrastructure is original and unchanged.

Hohm is launching only in the U.S. for now, but Microsoft says it plans to roll it out in other countries around the world over time–particularly in energy-conscious ones such as Germany. After the jump, a few screens of it in action.