Indoor Activities for Toddlers?

I am looking for ideas of things I can do with my toddler daughter this winter. She is 2 and a half years old. In the summer, we routinely went to the park, played in the yard, went swimming, but didn't do much indoors. Now that it is getting colder I am finding there is not much to do. I've taken her to Petsmart several times, and to the library, grocery store, etc... just looking for something more to where she can play and use some energy. Thanks in advance for any ideas.