We just got done with a science unit on invertebrates. One of the sections was on echinoderms (starfish, sand dollars..), and a suggested activity was to make starfish from salt-dough. (side note: Ever plunged your dry, cracked, winter hands into a bowl full of salt, flour, and water? Mostly salt? aaaAAAGGHHHHH!) So we made starfish, and carefully etched the five "spiny" rays and added texture, etc. We waited a long time (days) for them to dry so we could paint them. I was envisioning what kinds of realistic colors and designs the kids would come up with, and wouldn't they look pretty hanging on the wall with an "ocean" background?
Well, they did have a lot of fun. :)