I was out for a nice 3 mile BF run (my longest ever BTW) yesterday.  I did an out and back course, and I just happened to pass an old woman about a block before I turned around.  As I was running back she flagged me down and asked me "Why barefoot?" - not in a mean way, but more just curious.

I stopped for a few minutes to explain to her how it is good for your running form, helps you land on the mid-foot instead of the heel.  She seemed very interested and was very polite about everything.  She said thanks and I continued on my run.  It was kind of nice to get someone interested enough to ask instead of the dumb-founded looks I usually get.