The "invisible" shoes/huaraches are the best thing I can find for running any distance. A couple Saturday's ago, I headed out with a goal of spending 10 -12+ hours on my feet to prepare for a 50 miler on June 30th... a trail "race" with plenty of elevation changes. For about the first 8 miles I walked...then slipped on the 4MM huaraches and started running slowly...covering 41.5 miles total is just over 12 hours.
I prefer the huaraches for running over walking, but everyone is different and there are so many ways to lace/tie them on. Perhaps I just haven't found the best walking configuration. If you order, consider getting 4MM and 6MM...you can get two pair for less than most shoes. I've punched dozens of holes in my 6MM to make them lighter...and I think I've "perfected" a casual slip on lace/tie technique for running and walking. The 6MM are for replacing flip flops and running on rough stones.
I've never cared much for the way flip flops are not attached at the heal.
Direct link to shop huaraches or directions to make them... they are so low cost...not worth trouble to make an inferior pair imo... http://www.InvisibleShoe.com/go/Randy_Kreill