But now I see, you are probably speaking of this? http://www.bootybelt.com/booty-belt-packages/booty-belt-system.html
I already use tubing exactly like this, although not in this nifty design of theirs. Looks quite interesting to me. I use tubing to help a lot with hip stability, targeting gluteus medius for pain etc. Also works great during pilates side series. Without having tried it, I would say it looks very overpriced, but I'd love to hear what folks who are using it have to say.