Looking for ideas for a party with a 'Grease' theme.

I am having a "Grease" (the movie) themed birthday party for my daughter who is turning 6. I am making poodle skirts out of felt and am going to let the girls decorate them. We are going to have a "sock hop" and hula hoop contest. I still need an idea for party favors. Any suggestions?

Kshrum