David Brooks had a column, syndicated by the New York Times in August, titled "Dropping old names for new". In it he commended Laura Wattenberg's "obsession with names...and has transformed it into a window on American society, the Baby Name Wizard. He specifically extolled the blog for trends in baby names. If you have Java script, definitely check out the NameVoyager, which is not only interesting but visually cool.
Of course, the Social Security Popular Baby Names section is useful as well. In fact, I had so much fun with it that I had to blog about it earlier this year.