There’s only one extended edition. The first DVD release, the one your friend has, was the version you saw in the theaters. The second DVD release will feature a version of the movie that includes more than thirty minutes of previously unseen footage, complete with new score, special effects, etc, seamlessly inserted into the film.
This is, incidentally, exactly what they did with Fellowship of the Rings, and they will be doing it again with Return of the King. And they’ve been saying that they plan to do this for at least a year in advance of the release of the first movie. I honestly don’t know how anyone with more than a slightest passing interest in the film could be unaware of this, but threads like this still pop up about once a month.