ABC News- The Science of the Yawn

Did anyone catch this on ABC the other day?  It's about why we yawn.  I need to try the breathing through your nose trick that they mention.  I am a chronic yawner...according to them I guess it just means that my brain is working extra hard!
[linkhttp://abcnews.go.com/Video/playerIndex?id=3427139]http://abcnews.go.com/Video/playerIndex?id=3427139[/link]


I love those Diet Pepsi Max commercials (they showed one in the clip).  Has anyone tried it?