There's a nice article on ecological restoration in the Christian Science Monitor. I'll leave you with a teaser quote that caught my eye, but there's more to the article than just "kill your lawn".
Asphalt...is not the only surface that creates a boundary between people and the environment. “Mowed lawns surround most factories, schools, churches, and other buildings,” he says, “and they give nothing back to people or the environment.”
Even on a small scale, meadows and open wooded areas do much more than lawns to improve the quality of human life, he says. They are also cheaper to maintain, a concept that has special appeal in hard economic times.