Your guide to the resources that will help you put technology to work for your cause, this month with an environmental focus. Earth Day may have passed, but that's no reason not to try a little harder every day. Think of what will happen when everybody does.

Determine Your Impact

> It seems that if you run an environmental website, you need to offer a calculator of some sort. For overall carbon footprint, we liked the offering from Redefining Progress best -- and not just because it said we would need only 2.2 Earths if everybody lived like us, as opposed to the 2.7 reported by Earth Day Network. That's half an Earth! If you're short on time, Zerofootprint.net wants to organize the like-minded, social network style, but you can just use their One Minute Calculator.

> Then there are the more specific calculators. The Sierra Club lets you determine not only how much fuel, but how much money you would save if your current car met proposed new standards. There's even a Call to Action after you use it, so it's a good model, as well. And if you're concerned about your diet, you can score it for Health, Environmental Impact, and Animal Welfare. Just be warned that, apparently, eating anything at all is bad for the environment.

> Need more environmental calculations in your life? Suite101.com has a long list.

Use Less Energy

> After using those calculators, you may be a little concerned -- that's the sensation they're supposed to inspire, after all. 2.2 Earths? That's at least 1.2 Earths too many -- and even then, Shanghai, Houston, and Mexico City will still be smoggy.

> So, let's do something. Greener Choices breaks down household energy use by function. The Department of Energy has a list of ways to cut those numbers down, while Energy Star's site helps you find new, more efficient products.

> One of the hobgoblins of energy waste is Phantom Power Drain (which even sounds like a hobgoblin's name). If you walk into your living room at night and see blinking lights or the steady glow of LEDs, you're losing power, up to 15% of your total bill. Belkin's new Conserve power strip -- it comes with a remote control! -- can help stop PPD.

Make Every Day Earth Day

> Getting a new computer at work? Congratulations! Now, recycle that old one. Earth 911 and the Environmental Protection Agency both have information on how to keep your old compy from being dumped on India like a tech support phone call.

> You should also check out GreenPrint. Their software promises to eliminate "unwanted pages saving paper, ink, money, and millions of trees." 2.2 Earths worth of trees, we hope.

> Closer to home, you can get ready to ride your bike to work with these tips. Going out for sushi (on your bike)? Don't forget this wallet-sized list of seafood you should avoid. Oh, and: pack a lunch! Take-out litter generates 1.8 million tons of trash every year in the U.S.