John Mayer Style picking

This is a 3.63 minute video response from David MacKenzie on Nov 1st, 2008

Question:

"Kenstyle asked "I'm curious about John Mayer's technique in this youtube video: http://www.youtube.com/watch?v=YPvkSo1itgc&feature=related. He uses his thumb and index finger throughout the song and the net effect of this technique is that it sounds like a strum with a pick. Any help would be great. Thanks! Ken""