It's much more then you think.
One of the best periods of my life was when I was both working and living in Waltham, MA, and walking to work every day. Fun, relaxing, and cheap. Ah to revisit those days. I'm close in that I only work ~5 miles from my house, but Route 9 in Framingham is too scary to ride a bike on, so i'm stuck with my car for now.