The Doors of Durin by ktraphagen (Which is technically made out of Modulex, which is a smaller brick form, like Duplo is a bigger brick medium.)
If you'd like to check out more exciting Lord of the Rings, There and Back Again/The Hobbit, and Tolkien Lego creations, be sure to check out Bruce N H's new blog, entitled TolkienBricks (and while you're there, check out his other great blogs too!).
Just as a side note, I hope everyone has been enjoying the new content with Katie's fantastic posts. Now that schools out I'm hoping on getting into the Christmas/Holiday spirit with some mosaic posts and exciting new ideas.