If you want to read a fascinating and very learned exposition of the topic of women covering their hair, then download Rabbi Michael J Broyde's Hair Covering & Jewish Law: Biblical and Objective (Dat Moshe) or Rabbinic and Subjective (Dat Yehudit)? at http://traditiononline.org/news/article.cfm?id=105511
In case you haven't heard of Rabbi Broyde, here's a short piece from his Wikipedia entry:
Michael J. Broyde (May 12, 1964) is a professor of law and the academic director of the Law and Religion Program at Emory University. He is also a senior fellow in the Center for the Study of Law and Religion at Emory University. His primary areas of interest are law and religion, Jewish law and ethics, and comparative religious law. Broyde has published more than 70 articles on various aspects of law and religion and Jewish law, and a number of articles in the area of federal courts.
He is ordained (yoreh yoreh ve-yadin yadin) as an Orthodox rabbi by Yeshiva University and is a member (dayan) of the Beth Din of America, the largest Jewish law court in America. Broyde was the first rabbi of the Young Israel of Toco Hills in Atlanta, GA. He is married to Channah S. Broyde and has four children: Joshua, Aaron, Rachel, and Deborah.
Broyde is a prolific author and speaker on Jewish law, Mishpat Ivri and Jewish ethics. His work is frequently cited by other writers on his subjects of expertise.
In other words, he does know what he is talking about.