Done for a fan art contest a while back on Define Cynical (the Ozy and Millie fan forum). The theme was Ozy and Millie characters as superheroes, either existing ones or ones we made up. I decided to go with Dash and Violet from the movie The Incredibles. I suppose it would fit their personalities better if they were reversed (I find that happens a lot with them), but they'd still have the same outfit so it would just be confusing. Besides, Violet and Millie are both voiced by Sarah Vowell, so it's appropriate.

Oh, and if you don't already read Ozy and Millie... http://www.ozyandmillie.org