What is Harry Potter without the music? (In the films at least; they have yet to come out with a singing book.) Based on the theme music from the movies, the ringtone is free for download and easy to install. Download it here, save it, and upload it to your phone.
I was reading Book 6 of The Series, Harry potter and the Half-Blood Prince, when my phone rang. I answered it, spoke for a long time about boring work stuff, then hang up. I went back to reading, finished the chapter, and looked back at my phone. The idea dawned upon me then and now I bring you the my favorite ringtone of all time.