I've tried several barefoot / minimalist shoes and I keep coming back to these after I return all the expensive sooper-engineered ones.  They have a thin sole, they breathe well, they don't chafe, and they're sturdy.  My Riptides have over a thousand miles of trail running on them, and they've just needed a bit of Shoe Goo.

Don't bother with these, I've tried them all:
Vibram Five Fingers - falls apart
Merrell Tough Glove - ankle chafes
Nike Free - no ground feel, falls apart
VivoBarefoot - OK but lots of $$$$

Get a pair of Riptides, go down one size, remove the sole, and run circles around your trendy friends that grossly overpaid for their "barefoot" shoes!