There's only one in the area I live now, and you have to work a certain number of hours, every other week, which is pretty much impossible for us.
But you inspired me to look them up in the area I'm moving in August... it's sort of a "hippie town" so it turns out there's a bunch of them! One even lets you "shop" for your own stuff at their stand at a farmers market, so you aren't forced to take things you won't use. I'll definitely look into it further.