If you love barefoot trail running or are interested in giving it a shot, consider Vivobarefoot's Breatho Trail. Your feet will love you for it. It's completely flat and flexible all around with a large toe box, allowing your foot to move any way it wants to. The thin layer of protection allows for a surprisingly good feel of the ground. And if you want to feel the ground a little bit better, Vivobarefoot recommends that you remove the insole. The lugged outsole gives you a sure grip even in loose dirt and sloppy mud though you still have to be careful on slippery rock. The breathable upper mesh keeps your feet cool and dry while you give it a good workout running trails.
This was a great shoe. No longer available but the new ones are probably better anyway. Check them out at Vivobarefoot.