Lohan gets emotional as she calls Oprah live on air

Lindsay Lohan wept as Oprah Winfrey praised her on David Letterman's show last night.

The 'Mean Girls' actress - whose post-rehab attempts to get her career back on track are being chronicled in documentary series 'Lindsay' on the media mogul's OWN network - initially planned to prank call her mentor, but the retiring talk show host quickly blew his own cover and had a serious chat about his famous guest instead.