I've seen similar things before -- this one seems to be a British craze that's now making it's way into the US. Here's the link to the manufacturer's site below -- if you type in your zip code you might see places near you that have them so you can try them out before you buy. Obviously mail order is often the cheapest because you might save tax but at least you can try them on if you want! Also, if you do buy online, remember to check out
www.retailmenot.com to see if there are any coupons for the store in question!
http://www.thefitflop.com/