When Caroline Kennedy managed to say “you know” more than 200 times in an interview with the New York Daily News, and on 130 occasions while talking to The New York Times during her uninspired attempt to become a hereditary senator, she proved, among other things, that she was (a) middle-aged and (b) middle class. If she had been a generation younger and a bit more déclassé, she would have been saying “like.” When asked if the Bush tax cuts should be repealed, she responded: “Well, you know, that’s something, obviously, that, you know, in principle and in the campaign, you know, I think that, um, the tax cuts, you know, were expiring and needed to be repealed.”
Christopher Hitchens on using "like" as a filler word
It's, like, a pretty good article.