Tin Can Blocks
My guild is doing a tin can block exchange this year. Everybody puts half a metre of fabric in an opaque container (a large coffee can works, hence the name). Label the outside with your name and desired block size - most go for 12" finished. Each meeting we take someone else's can and make two blocks using some of the included fabric. When the cans go home to the owner there are enough blocks to make a quilt.
The can I currently have has been my favourite so far. The owner put four smaller pieces of coordinating fabric and I love the blocks created from them. Each time around I think the challenge gets harder and harder as I take it a challenge to coordinate with the blocks already made. Here are the blocks in the can. Mine are the two on top. I have no idea when the green was added!