I recently encountered a Studio Executive who after yammering on about collaboration and respect for Filmmakers declined to shake my hand and the hand of another director also present. (Awkwardly begging off while mumbling something about illness-the exec looked healthy to us by the way.) I felt insulted as did my friend.
This got me thinking about the hand shake and it's implications. (Here is an overview of the history of Hand-Shaking.) I was taught to always shake hands as a sign of respect and I plan to continue to do so.
For the hand-shaking challenged here is an excellent review.