No -- previously I've only written some parodies (like a Star Wars-esque "Episode VI: The Return of Voldemort" -- before HBP came out -- I recently wrote a slightly more refined "3-minute Deathly Hallows ala George Lucas" that I'll put up on my website shortly). And whenever I read a novel, I'm always thinking about how to translate it to the big screen. But this is the first complete screenplay adaptation I've written down. I have a film adaptation of The Phantom of the Opera fully fleshed out in my mind that I plan to write down soon (it's more faithful to the novel than any movie or theatrical production I've seen or read about, though I plan to give it more backstory via flashbacks). I might tackle HBP if I have the time though I probably won't because it's not as fun a project as Hallows -- I don't envy Kloves' job of adapting HBP into a movie! It's all flashbacks and has maybe a half hour of plot and action. Another movie adaptation that I've had in my mind is The Dark is Rising -- so imagine my surprise when I heard that was actually going to be made into a movie! The trailer didn't really capture me though, so I don't know if I'll like the final product.