We have a BOM at our local LQS. It's free as long as you complete the previous months block. The store provides one fabric each month for that block and you get to choose the rest of the fabrics that go into the block. You bring your completed block inb4 the end of the month they hang it up and everyone votes on their favorite. There are three prizes with gift cards! at the end of the year we have a few months to complete the quilts then we have a "party" to show off our finished quilts the store provides appetizers and drinks. It's a lot of fun.
I am currently doing 2 BOMs through this Quilting Board one is the houses the other is the stars. We post our finished blocks on line so we can oooh and awe over everybody's.