For the last three years I have participated in the Block Party that is organized by one of my favorite quilt designers - Lynda Hall - of Primitive Pieces by Lynda. Lynda designs a quilt block and chooses a color palette - then people sew them up and send her quilt blocks. She arranges to have them pieced together, quilted and auctioned off to raise money for Quilts for a Cause to fight breast cancer. I just finished up a number of blocks and will get them in the mail to her soon.
I know there is still plenty of time for people to sign up, so if you are interested in helping out just send her an email telling her you are willing. She will send you the pattern and instructions on how to make the block - they work up really quickly and can be scrappy - which makes it so fun.