I created this NO MESS PAINTING for my infant and toddler classroom. They had a blast mixing the colors and making footprints. The infants even joined the action by having tummy time and exploring the colors. Very easy and cheap idea!!! Comment for more info. TGP
Balloon painting! I did this on the first day in my Creative Expressions in Play course (in Spring 2010) and it was so much fun, so I would imagine that it'd be as equally, if not more, fun for Pre-K classes!