You might try flower pounding (google it for articles on how to do it). One year we had a set-up at our quilt show where children were encouraged to try flower pounding, and later someone put all the blocks they made into a quilt. Everyone could optionally bring their own flowers. Each person could make a block, sign it, and you could put them into a quilt. You would be amazed at how much fun adults can have when they're allowed to whack at something with a hammer! It's a great ice breaker, and everyone laughs and has fun. (Everyone not doing the pounding gets a headache though.)