During the month of August Carlomagno gives up taxis. Of course for a New Yorker this is a bigger sacrifice than it is for those of us who live in Bridgewater, Massachusetts. She survives the month with sore feet, and a fatter wallet, and uses the money to treat herself to a pedicure. She learns her way around the city better as she walks, and takes buses and the metro instead.
My husband and I have almost always been a one-car family. When we have lived in places with public transportation we tried to use it whenever possible, and in our current location have opted to live next to where we both work, so the car can stay at home, unless it is our turn to drive our daughter's car pool. Our decisions are based both on finance (we not only save on gas, we get a discount on our insurance for not commuting) and in our desire not to waste fossil fuels. On the rare occasions that we need to be in two different distant places at the same time, we find that our friends are happy to help.