The new thing on Facebook is people looking up the song that was No. 1 the week they were born, then posting the video on their Facebook wall.

Even if you're too cool to participate in Facebook trends, it actually is interesting to find out what your "Birth Song" is.

To find your song, go to Wikipedia and look up 'List of number-one hits.' Then select United States, click on your birth year, and find the week you were born. Then prepare to feel old.