The single most important thing you can do to reduce your impact on the environment? Drive less. Even if you’re not willing (or able) to become a full-fledged bus chick/bus boy, you can still make a difference.

This Earth Day, sign up to participate in the City of Seattle’s One Less Car Challenge, and give up one of your cars for a month. Not only will you be helping to reduce pollution (and congestion, and sprawl, and dependence on fossil fuels) in our (breathtakingly beautiful) corner of the world, you’ll also be eligible for all of the fabulous prizes and incentives the program offers.

I’m guessing that, come May 22nd, you won’t want to go back.