A friend of mine had a nicely designed site built upon a custom CMS. He wanted to add a blog built upon the WordPress framework since he has used it for other projects and liked the features and functionality. I used my personal theme framework and meshed it with his main CSS file along with a few modifications to allow him to blend the blog in seamlessly with his site.
Things I learned: Modifying a theme to include the styles of an existing site as well as the navigation elements in order to create a seamless experience. New ways to use WordPress to add on functionality to an already existing site.