I've been shopping around for some running sandals and I've been leaning towards the Xero shoes. However, I have to admit that the idea of making my own sandals/shoes sounds really appealing. I know I'm not the only one. Has anyone here experimented with different material for the soles besides rubber? I know for a lot of reasons, durability comes first to mind, it's the most obvious choice, but what else have you heard of being used or maybe tried yourself?