Hi Lizzy,
Firm YaYa's is the 'unofficial' website for exercisers who are partial to Firm workouts. I say unofficial because the supposed official site, firmbelievers.com, charges for people to use it. So for those who enjoy the Firm and think that charging people to post about their experiences is a bunch of hooey, they post at YaYa's.
They also have a swapmeet section on that forum where you can list videos/dvds you are no longer using for trade or sale. It's a neat feature that I personally wouldn't mind having on this site too.
I frequent YaYa's, videofitness, and this site, although I post and check in here by far the most of the three. All three of these sites have their strengths and weaknesses. It's just whatever grabs ya.
HTH