Re: size. The purple pair that Dismom bought are the Cayman style. I can tell by the part closest to her ankle...there's like a textured band there. The Caymans have more sizes...they're full sizes (ie, 7, 8, 9, etc). The Beach style that most people seem to buy run by double sizes (ie, 4-5, 6-7, 8-9). The Beach and the Cayman look exactly the same, except that the Beach has a "crown" design at the top rather than a straight band. I tried on the Beach style several times and they never felt right. Finally, when I found Caymans, they felt great. I have two pairs...blue and black. Hope to buy more.
I got my Caymans at Bob's Stores.
Hope this makes sense and helps!
Oh, BTW...more about size. If you look on the bottom of the Caymans, they show men's sizes and women's. I wear an 8, so on the bottom, it says "M 6, W 8".