I have the Five Fingers (to increase the mileage-to-blister ratio and to deal with the hazards of certain surfaces, and just to freak people out), but also run barefoot as well. I don't have convenient access to grass I can trust not to be hiding scary stuff in it, and feel that replacing one crutch for another - the cushioning of the shoe with the cushioning of the ground - is partially defeating the purpose anyway, so I do my barefooting on pavement. I do my longer distances in shoes because keeping the weight off my heels as is necessary without the padding makes my calves give out after 2-5 miles depending on how fresh i am and how successfully i conserve energy though better form, though that threshold is increasing with time. And my stride in shoes is now pretty much the same as it is barefoot.
I'm not totally anti-orthotic or anti-high-tech-shoes, but i think they are generally best considered as crutches - transitional aids (I'm not qualified to comment on their presumed applicability to a small minority of people who may be diagnosed with some specific medical condition that makes them necessary). The exclusive emphasis by shoe companies and a lot of doctors on pronation as the root of all evil and on their particular products as the only way to prevent over-pronation strikes me as virtually a scam; humans have been distance-running for millions of years before this stuff existed. There's no substitute for adequate form and conditioning.
Barefooting is not a panacea and can cause new injuries if you don't ease into it, as most people's feet and lower legs are probably atrophied from a lifetime of wearing shoes. But i've found it not only appeals to my inner purist, but for me personally has been an excellent catalyst to revamping my running form, learning to listen to my body, and, once i had taken the impact off my knees so that i actually could run at all, getting myself a deeper practical education on technique, exercise physiology, anatomy, and training methodology so that i can hopefully run harder, farther, and have more fun in the mountains. Plus, "Born to Run" is just a fun book to read.
BTW, i've gone from being winded and my knees giving out in 1/2 mile 4 months ago, to a personal best half-marathon last weekend. My injuries aren't entirely gone, but they're getting more manageable and will hopefully be gone before too much longer.