Roughly 30 minutes ago a thought occured to me and I had to put it to the test.  I quickly typed the following message on Twitter:

I wonder if a "Yaaawn" is Contagious via Twitter. If you read this and shortly thereafter yawn, just for fun RT this.

The results less than 30 minutes later are the following:

Click Image to see latest "Yaawn" update

So now I'll pose the same challenge to my fellow AR Members... IF shortly after reading this post you yawn, come back here and let us know via a comment or write your own "Yaawn" post to put your fellow readers up to the test.  If you use Twitter RT my original post and see how far this gets.