D.W.
I love the clown idea and someone to make balloons idea. I also think you should do a puppy cake, pin the tail on the puppy for ALL of kids (my son is almost 2 and would need help but he would love to be involved). A cake walk with puppy prints (have parents help them go around and stop) -- prize=they get a cup cake. Then give a party prize bag as they leave. Have a great time!