I've found several on yahoo groups. Just search for the types of fabrics you want.
Generally they work using a database (that is part of the group's site). So someone agrees to organize, say, PUL. So they make database, saying how many yards is the minimum order, and wait until it fills up. so, I order 10 yards of red PUL, you order 3 yards, and someone else orders 12, etc etc. All of the groups yardage adds up to equal the minimum order, and everyone saves money. Once minimums are met, then the "leader" askes for payments, orders the fabric, cuts it when it arrives, and then askes for shipping payments. Your fabric is shipped after you pay. In most groups you'll pay two different times : once when the group orders the fabric, and once when it arrives and is ready to ship. This process can take several weeks (or a month or two if it is a fabric that has large minimum orders), but the $$ savings is totally worth it. Some groups also co-op notions like aplix and snaps.
I hope this helps!
