Here is a vindication of the barefoot set from Boing Boing by Cory Doctorow:
Adam Sternbergh's long investigative New York Magazine piece, "You Walk
Wrong," makes a compelling case for shoes as inherently damaging to
your feet and spine. I have very flat feet, which has always meant
problems with my hips, knees and back, and I've work custom orthotic
inserts since I was a teenage. Last year, I picked up a pair of Vibram Fivefingers
"barefoot shoes" that do a pretty good job of simulating the experience
of going barefoot without the tetanus and laceration risk, and I've
done a lot of city and country walking in them, and I have to say, my
back and knees and feet feel pretty damned good after a couple days in
them.

At
first glance, this seems like a sensible and obvious approach—to work
with the foot, not against it. But it represents a fundamental break
from the dominant philosophy of shoe design. For decades, the guiding
principle of shoe design has been to compensate for the perceived
deficiencies of the human foot. Since it hurts to strike your heel on
the ground, nearly all shoes provide a structure to lift the heel. And
because walking on hard surfaces can be painful, we wrap our feet in
padding. Many people suffer from flat feet or fallen arches, so we wear
shoes with built-in arch supports, to help hold our arches up...
Admittedly, there’s something counter intuitive about the idea that less
padding on your foot equals less shock on your body. But that’s only if
we continue to think of our feet as lifeless blocks of flesh that hold
us upright. The sole of your foot has over 200,000 nerve endings in it,
one of the highest concentrations anywhere in the body. Our feet are
designed to act as earthward antennae, helping us balance and
transmitting information to us about the ground we’re walking on.
But (you might say) if you walk or run with no padding, it’s
murder on your heels—which is precisely the point. Your heels hurt when
you walk that way because you’re not supposed to walk that way.
Wrapping your heels in padding so they don’t hurt is like stuffing a
gag in someone’s mouth so they’ll stop screaming—you’re basically
telling your heels to shut up.
And your heels aren’t just screaming; they’re trying to tell
you something. In 2006, a group of rheumatologists at Chicago’s Rush
Medical College studied the force of the “knee abduction
moment”—basically, the force of torque on the medial chamber of the
knee joint where arthritis occurs. For years, rheumatologists have
advised patients with osteoarthritis of the knees to wear padded
walking shoes, to reduce stress on their joints. As for the
knee-abduction moment, they’ve attempted to address it with braces and
orthotics that immobilize the knee, but with inconsistent results. So
the researchers at Rush tried something different: They had people walk
in their walking shoes, then barefoot, and each time measured the
stress on their knees. They found, to their surprise, that the impact
on the knees was 12 percent less when people walked barefoot than it
was when people wore the padded shoes.