I just saw this today on fitsugar and instatly started wishing for it. The reviews on Amazon are extremely encouraging. Besides, I've always loved ballet but never had the chance to practice it (expect learning some stuff from a book as a kid, but how much dancing can you learn from a book?). And man, 9$, that's so affordable (well, not for me at the moment, my budget really says "student budget" right now). I think that would be a wonderful change from yoga in spring or summer.