Buzz Dixon directed me to this neat site that's all about names. They have a Java program over there — it should work on most but not all computers — that displays charts of the popularity of the 1000 most common first names. You can enter "George" and watch how it's declined in popularity or enter "Jason" and watch a big spike in the seventies and so on. I didn't particularly notice trends linked to the fame or infamy of specific prominent celebs, but I suppose there's some of that in there.