Our pianist plays "wiggly" music* while the kids wiggle, shake and jump around. I then pick who's the wiggliest, and that child comes up and picks from the wiggle jar. I may need to start using the picking sticks, though, so as not to keep picking the same children over and over.
We have pom-poms, with the song attached on a long colorful neon rectangle piece of paper bent back and forth to look 'wiggly' (do you get the idea? I need to take a picture). These wiggle worms from Choristor's Corner are adorable, too.
*wiggly music.... like, a triplet of high notes over and over. Get it? Sort of?