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!
(Sense of touch) put different objects in balloons and have the children guess what each one is. Then, open them up to see what it is. (Tie with elastics so it is easier to open.) To further the lesson, make a chart of prediction and result.