I saw it on one of the tv shows however the curved pieces were not flat pieces of fabric for lack of better words - she kind of folded the fabric in pleats as you curved the fabric around - does that make sense?
I know this isn't what you had in mind but...
http://www.paperpanache.com/howto/machcurv.htm
I also found this book...
http://www.amazon.com/Paper-Pieced-C.../dp/1564773027