The now infamous 2010 Internal Revenue Service conference in California — where goofy, expensive video parodies were shown — also featured $135,000 in spending on outside speakers like a "happiness expert" and a session titled "Leadership Through Art," congressional sources briefed on an upcoming inspector general's report told NBC News Monday night. The IRS hired 15 speakers to present at the conference in Anaheim, Calif., including $11,430 for positive psychology guru Shawn Achor — referred to as a "happiness expert" by the sources — to lead a 90-minute workshop and $17,000 for artist Erik Wahl to hold a session that...