Doodling

How do you perceive doodling in meetings?  I respect the need for doodling as a way to help people maintain their attention and focus.  I have a colleague who brings her colored pencils and sketchbook to longer meetings, just for this purpose.  But for me, I know when I start doodling that it either means that the meeting has become boring, or an extremely uncomfortable conversation is taking place and is not being handled well.  That's when I put my head down and start doodling.