At first glance, barefoot running shoes seems like an oxymoron: I mean, how can you have shoes and be barefoot?

Well, as this latest evolution of running shoes shows, you can have your cake and eat it too: barefoot running shoes make it so that you can get that barefoot running feeling and still protect your feet from the worst our roads have to offer.

As a barefoot runner attempting the first ever barefoot run across America, I can tell you a little about what that "worst" is. You see, while I used barefoot running shoes extensively myself while preparing to run across America, I have run the 600 miles so far entirely barefoot, without the benefit of any kind of protection.

And, as you will see, that presents some hazards. For example, the stretches of broken beer bottle glass along the roadside in New Jersey. The goose poop which is simply unavoidable in Central Park, NYC. And then there's what I affectionately call "tar knives" that I encountered in Ohio and Pennsylvania...all of which could have been avoided if I was wearing barefoot running shoes. But I wasn't.

I'll tell you more about the horrors of barefoot America in a moment (including exactly what "tar knives" are) but first let me explain what barefoot running shoes are all about.

Barefoot running shoes are also called "minimalist" shoes or "transition shoes" by the barefoot running community. They are often used for transitioning from wearing fully padded, "normal" type running shoes to going completely barefoot. Or, they may be the shoe of choice for those who want to "run barefoot" but don't like the idea of their sole actually touching the dirty ground.

In either case, barefoot running shoes come in a few styles, for example the Newton Running Shoe, which I have heard great things about but not tried out as actual barefoot running shoes myself, and the Nike Free.

I had worn the Nike Free's myself for a few years before I started barefoot running, just because l liked the feel of them (and I really wanted to design my own shoe online!). Again, I haven't actually used them as barefoot running shoes, just as I say for wearing "out and about."

The barefoot running shoes that I have tried personally - and actually used to train in for hundreds of miles while preparing to run barefoot across America - are the Vibram Five Fingers. These barefoot running shoes really live up to their name; they even have 5 individual, separated toes that get you very close to the actual stance and motion of running barefoot.

These barefoot running shoes can be great for training to run totally barefoot; or if you don't like the idea of stepping on goose poop or broken glass EVER, maybe you would prefer to use them at all times for barefoot running. Personally I didn't feel I could say that I ran "barefoot across America" unless I used them only for training, but then took my barefoot running shoes off while on my cross country odyssey.

Which is why I ended up crawling at a snail's pace over the "tar knives" in Ohio and Pennsylvania. Otherwise known as chip-n-seal, this is essentially gravel that has been poured over liquid tar and left to harden into miles of sharp rocks that stick up and don't budge when you step on them. A pair of barefoot running shoes would have saved me that torture.

And then there was the crushed cinder they "sand" the roads with in West Virginia in the winter; did I mention that? Yep, it would have been really nice to wear my barefoot running shoes over that stuff, and maybe not have had to pick cinder shards out of my foot all night. Crazy not to put them on, right? But that's me: stubborn, tough-footed, and (some would say) completely, certifiably crazy.