I do allot of both as well as gaming. I think I am more of a geek lol !
I too would rather consider myself to be a techno-geek rather than a nerd... To me, a nerd is more anti-social (doesn't want to go out in public, etc.) whereas a geek is just more into cerebral interests that may be considered to be introverted (eg reading, gaming, etc.) but still isn't fearful of social interests. For example in the
Big Bang Theory, I tend to think of Sheldon as a true nerd whereas Leonard is more of a geek.
As for the OP's question about reading vs. a movie, I too don't think this really distinguishes between a nerd and a non-nerd as some Star Wars fans would argue that the original movies (Episodes 4-6) are still the best things to come out of the Star Wars universe and that the books are just wannabes.
For me, I don't really have a preference between a good movie and a good book (maybe I'd lean towards a book mostly since my enjoyment in reading would last longer than my enjoyment from a movie)... However books tend to do a better job at really getting into the motives of each of the characters in ways that is difficult for a movie to do (very few movies have an actual narrator that can speak to what a character is
thinking about at any given time). Then again because movies are relatively short, they also tend to be more intense and fast-paced than a book. For example, I actually enjoyed the movie version of Jurassic Park than I did the book, even though I was studying molecular biology at the time and easy understood the scientific premise of the story that the book spent more time talking about. Sometimes books can get too long-winded trying to describe a scene and set the mood while a movie can achieve the same thing in less than a minute (as in "a picture can say a thousand words").
Actually I seem to be liking television series more than I do movies... TV still is able to have many of the special effects that movies have, yet because they can tell a story over a longer period of time than a movie can, the characters, plots, etc. all tend to be better fleshed out in the TV shows. For example, even though I love the books the best, I'm glad that the Game of Thrones series appears on TV rather than them trying to reduce it into a movie.