My favorite Halloween quick activity is to have a Monster Dance Party. It's like freeze dance. Put on a spooky Halloween song and tell the kids to dance like a Mummy. Then after a while, pause the music. They will freeze and tell them to dance like a ghost. This goes on and on. Today, we were dancing like blood and pumpkins.
Eric made a great Halloween mix for me from songs he found at The Devil's Music blog. Fun stuff!