I just bought a pair of Keen sandals, and I love them so much I have to share with the world (others may have done the same, I just didn't spot anything). I have not had a pair of sandals this comfortable before.

Size reference: I have wide feet, somewhere around a womens 8-9. Running shoes men's 8EE. Biking shoes mens 41.5. Normal shoes, 8-9 womens if they are wide, 7 mens (sometimes even have to go wide mens, sigh).

Keens are apparently a little narrow (or average at least), I didn't even try the womens' version on. The nice helpful man at REI said not to bother after I said I had wide feet. I put on the mens' size 7 (Newport H2s) and they fit like a dream. I don't have to "lace" them up at all, and they fit around the top of my feet pretty well (they will stretch/form as we go, too). The heel piece at the end is a little loose on both feet, probably because I'm in men's shoes.

For those of you with less Fred Flintstone-y feet, a friend of mine has the womens' version. She has narrow feet and "laces" hers up pretty tight. She loves them as well, and has no complaints about fit.

A little hard to get on (as is customary with a lot of sandals and wide feet), I have to push my foot through then worry about adjusting the top and heel. I do not feel constricted at all in them after they are on, though. The arch support is pretty good, my feet don't hurt when I wear them all day, and nobody has to look at my purple smashed toe They do have anti-microbial footbeds so hopefully I won't get "sandal feet" AND I can put them in the regular wash if they need to be tuned up a bit.

I'm not sure how popular they are in other places, but out here in the NW I see Keens a lot. I wish I could bike in them...