I read an enlightening article last night on Yahoo News.  It appears as if our president is a cross-dresser.  Specifically, he likes dresses from Gap.

You can see the entire article on Yahoo Shine.  Let me quote a specific section for you:

"On Friday, Obama left for Camp David with the president wearing a blue-patterned dress from the Gap."

This sentence proclaims, quite boldly I might add, that the president left for Camp David on Friday while wearing a blue-patterned dress from the Gap. 

The sentence would have been entirely different had they simply put a comma after the word "president".  Doing so would have then indicated that another Obama (Michelle would be assumed in this case) went to Camp David with the president...and that the OTHER person (as opposed to the president) was wearing the aforementioned blue-patterned dress from the Gap.

Who knows?  Maybe the absence of a comma was intentional because the author knows something that we don't.  Perhaps President Obama is attempting to reach out to cross-dressers in his own personal way.

Or perhaps they just forgot a comma.