Earth Hour 2008: Eco-fun in the dark. Turning out the light became a show of environmental solidarity on Saturday, when individuals, cities, and even entire countries turned off their lights between 8 and 9 pm for Earth Hour.

This campaign to bring attention to global climate change first happened last year in Sydney, Australia, but became a worldwide event this year. People around the world celebrated by stargazing, having candlelit dinners, and on the isle of Aegina in Greece, even participating in a candlelight march.

Missed the dark this year? Don't feel left out. Just sign up for the 2009 event!

EcoTuesday: Green business networking in your town. Starting a green business — or just thinking about it? EcoTuesday, a "Sustainable Business Leaders Networking Forum" that's spreading to cities around the U.S., might be just the social networking event you're looking for. This recurring monthly event invites the green biz crowd to mingle, network, and hear from eco-experts.

Atlanta, Los Angeles, Minnesota, San Francisco, and Seattle have joined in the green networking fun. If EcoTuesday isn't in your town yet, sign up to become an EcoTuesday "Ambassador" yourself, and get things started.

Earth Day preparation: Get your LILI score. Here's an easy way to figure out how to reduce your footprint on the earth. Low Impact Living's Environmental Impact Calculator lets you see how eco you are compared to others in your 'hood — then recommends actions you can take to get even more eco.

Tips range from simple acts like changing out a light bulb, to more involved ones like installing solar panels. And to help you figure out what project to tackle first, each recommended action includes information about the initial cost, the annual savings, and the footprint reduction that will result.

Get calculating before Earth Day on April 22 — then make an Earth Day resolution to reduce your footprint!