...unless you count bare feet, of course.
Looks like Soft Star Shoes is almost ready to offer their running moccasin on their website... and it looks sweet!
Grabbed this picture from their blog.
I've done a little running in my Vileys, also from Soft Star, and it felt great. They don't have all of the toe movement and feel that Vibram FiveFingers KSO have, but they come pretty close, and they're warmer. They've become the only shoe I wear when I'm not in uniform. I think Vileys would be a little too warm for summer, but these new ones look like they'd be perfect.