Early in the year I sold my car (1987 Nissan Exa) and bought a flat-bar road bike. A Giant CRX-4 to be precise. So far I have been extremely happy with it, the 12km commute to work every day takes me about half an hour and I think driving would only be about 10 minutes quicker.
Today I was thinking about what the cost saving of riding everywhere is. I price the petrol of driving a car at approximately $1 per 10km (this is actually getting further and further from the truth as petrol gets more and more expensive), registration is around $700 a year and insurance is about that again. I think I can just about justify to myself the money I have spent on my bike. That is without factoring in how much fitter I am.