We had an event at work called "On the Go". Charlie being the great dad he is brought Maura up to enjoy the festivities. She was able to ride a school bus, walk around a police boat, and do fun crafts.
There was also a "carwash". Many of the activities were brought inside because it was cold and rainy outside. Amazingly, the kids really didn't care that there wasn't real water and bubbles. It is much easier to pretend when you are a preschooler :)