Lisa, that is a great article.I learned the rule of thirds many years ago. Sometimes hard to work with. But, if I take an image that may violate the rule, and use a piece of paper to cover up parts of the image either vertically or horizontally, I come up with many surprises. Good stuff. Thanks!
On the same subject, this curiously-named website has some very good info. I have no idea why it's called 'morgue file' but trust me there's nothing to do with corpses on here: http://www.morguefile.com/docs/Classroom
I though some may find this article helpful. It gives guidelines for taking your photographic compositions beyond the rule of thirds.
http://photo.tutsplus.com/tutorials/composition/master-the-art-of-photographic-composition/