There is quite an interesting article in Yahoo Health that talks about the common myths and truths about our feet.
Example, wearing flip flops may not be the best option. Well, all podiatrists will surely agree that high heels are bad for your feet, knees, back and posture especially if typically worn for long hours.
Diabetics will need to take special care of both feet and as such, going barefoot is a bad bad idea.
Still, for most, I believe going barefoot on the earth is good for your health. Most of the time, we walk on concrete or tiles. We spent our lives surrounded by electronic gadgets such as computer, TV, MP3 and mobile phones. Our bodies will absorb ions due to the proximity and the hours that we spent exposed to these items.
By swinging your hands back and forth (in front and back direction), you can clear meridian blockages along your hand and the surrounding area of your torso. I tried that one day when I was not feeling well and immediately felt better (from the swinging and having my bare feet with direct contact of the earth in my garden).