A friend left her rainbows over at my house just before she moved to New York. She told me to keep them, and I loved them so much that when I wore them out I had to get another pair. I attended a very preppy highschool, and rainbows were the ONLY sandals girls could wear (yeah, weird, huh?) At any rate, they are very, very durable: At a camp one year, my friend lost his rainbow in the ocean, and it washed back up THREE WEEKS LATER, still intact (but covered in barnacles, lol). The quality of leather is great, but if you don't approve of wearing animal products they also have a very nice line of cloth sandals.
The only things about rainbows to watch out for is that the tread wears thin fast, and sometimes the dye in the can discover your feet, but only if you leave your shoes out in the rain and then have the genius idea to put them back on immediately.
These shoes conform to the shape of your foot, and are super comfortable. I wouldn't recommend walking long distances in them, though, as like most sandals they don't provide a lot of foot support.