A new study shows that doodling in lectures or meetings actually helps you retain more information. Read the full article in Time magazine Feb 2009. As I chronic doodler myself I can attest that it does help me concentrate, but it's nice to have this official validation.
One theory about why doodling aids memory is that it keeps you from daydreaming which takes up more of the brain's resources and can distract you from paying attention. Doodling takes up just enough of the brain's resources to stop it from daydreaming, but not so much that you don't pay attention.
