I live in Osaka, Japan, a city with one of the best mass transit systems in the world. I walk to the supermarket because it's right across the street. There's a Korean grocery downstairs about 30 seconds from my front door. There are probably 10 supermarkets within a 5 minute bicycle ride, and people frequently sell vegetables on the street about 2 minutes on foot from my apartment. I do all my shopping on foot or bicycle, although I do take the subway/bus/streetcar quite often. I also travel a lot, and I've been all over Japan by train and bus.
New Orleans was comparable, preKatrina, but on a much more human scale (few buildings over 3 stories tall, greenery abounds in small areas in Lower Garden District).

I had 5 places to buy food within 6 blocks.  Nearest bank, barber, tailor & insurance agent all 4 blocks away.  Two world class restuarants within walking distance, and many more just damn good ones :-)  Office Depot 7 blocks away, main Post Office a mile away.  Much more on streetcar line.