Last guy on there was some old dude singing his own song called "Pants on the Ground". I thought it was pretty funny, but saw Fallon's take:
Late Night with Jimmy Fallon - Video Blogs - Neil Young Sings "Pants On The Ground" - Jimmy Fallon's Video Blog | NBC Official Site
Late Night with Jimmy Fallon - Video Blogs - Neil Young Sings "Pants On The Ground" - Jimmy Fallon's Video Blog | NBC Official Site