I've not joined in any significant way the discussions about DNA because I'm in the "wait-listen-learn" mode on the topic. I'm quite interested in the matter. And I have submitted a sample to the database maintained by the Sorenson Molecular Genealogy Foundation, but no matches as of yet.
I mention the DNA issue this morning because there was yet another article about it in the New York Times yesterday. The articles in the popular press are interesting, but some of the most educational writing on this topic may be found right here in the blogosphere. Blaine Bettinger, "The Genetic Genealogist," is the "go-to" guy for me. And recently, Tim Agazio has used his Genealogy Reviews Online to explain his personal experiences with DNA testing. These have been very valuable articles and I recommend them.