Sizing information and online store available at the company website: Vibram Five Fingers
I'm currently reading Born to Run which has me interested developing my barefoot abilities (and also using Vibram shoes when barefoot isn't practical).
Last week I went to a running store that carries Vibram and tried on Sprints, KSO, and Float models. I liked the KSO best but the store had to order my size. I should have them in about a week.
I've been walking and running short distances in my barefeet for the last several weeks. It's amazing how much different your feet and lower legs feel after three or four sessions barefoot. If you're interested in learning more, check out the Google group for Minimalist Runners.
Sorry, I had links to all references above but the system won't let them through because I don't have enough posts yet. Google any of these terms and you should find the information.
Alan