we had one that we each contributed a 1/2 yd of batik--the coordinator then took all the 1/2 yd cuts and subcut into different sizes, those were put into a brown sack and we drew out one of each of the different sizes and could add another 1/2yd of our original batik to our creation--very interesting! Some did some awesomely creative stuff--can't say I did as it seems I didn't get enough light color batiks and wasn;t very creative.
then there's always the challenge of doing a small quilt depicting a song title or phrase.