ethusiasts of the hypnotic genre will already know this site ; http://www.warpmymind.com/
which deals with a whole range of different fetishes that can be experienced with hypnosis.
A recent add only two weeks ago is one to become a Barbie Doll, but seems its not free, you need to sign up for a month to several month pass to the site.
Still there's over a 180 people who downloaded it and are now becoming dolls....
but check out the yahoo group dollcollective for a what may well be the source file they're working from.