Jen and I had plans to do a couple of things in San Francisco on Saturday. We took BART as we nearly always do. Neither our house nor one of our destinations was close to a BART stop; by day's end, we'd walked more than four miles (four different legs of the trip had been about a mile on foot each.)
Walking a mile takes only about 20 minutes for most people, barring physical difficulties -- if those apply, this entry won't be very relevant. But a lot of people who could walk a mile or two automatically consider it too far, and search for an alternative. A lot of times, walking can beat the alternatives.
It's generally free. It's often faster than mass transit for short distances. It's exercise. It has a low carbon footprint. And you really get to see the bit of the world you're passing through.
Of course, you'll probably sweat. You'll need comfortable shoes, and, if you're carrying anything, you'll need a comfortable way to do so, like a backpack. If it's daytime, you may need appropriate precautions against sun exposure. Fashion might be a casualty, so if your destination is a black-tie event, you might want a different conveyance.
The rest of the time -- maybe walking a mile isn't so bad.