Alot could be said for people moving back into urban areas and walking/biking/public transit to work, but it seems that solution is rarely brought up in such discussions.
Indeed, lifestyle changes that lesson one's driving miles would make more of a difference than anything. I don't understand why people want to live 40-50 miles away from where they work in the first place. That's 10 hours of your week wasted just sitting in a car (assuming you don't have to deal with too much traffic). I'm much happier living about 8.5 miles from work even if it means living in a more urban setting. Ideally, it would be even less but I couldn't afford a place that would have the combined distance between home and both Lisa's and my work places (both in the 8-10 mile range) less than what we have now.