Actually, if you look up Britt's entry in the IMDB [http://www.imdb.com/name/nm1591584/] you'll find no less than 21 soundtrack credits!
What the hell -- here they are:
Soundtrack (21 titles)
2011 Horrible Bosses (writer: "The Underdog")
2011 Hall Pass (writer: "The Mystery Zone")
2010 Late Night with Jimmy Fallon (TV series) – Episode #1.289 (2010) (writer: "Nobody Gets Me But You")
2010 Late Show with David Letterman (TV series) – Episode #17.99 (2010) (writer: "Got Nuffin'")
2009 I Love You, Man (writer: "The Underdog")
2009 17 Again (writer: "The Underdog")
2009 (500) Days of Summer (writer: "The Infinite Pet")
2008 Cloverfield (writer: "The Underdog")
2007 Chuck (TV series) – Chuck Versus the Helicopter (2007) (writer: "Don't Make Me A Target")
2007 Nancy Drew (writer: "The Delicate Place")
2007 Friday Night Lights (TV series) – Nevermind (2007) (writer: "I Turn My Camera On")
2006 Stranger Than Fiction (Way We Get By, Small Stakes, Vittorio E, Turn My Camera On, Mathematical Mind, Book I Write)
2006 Fast Food Nation (writer: "Was It You?")
2006 The Darwin Awards (writer: "My Mathematical Mind")
2005 Standing Still (writer: "The Way We Get By")
2005 Waiting... (writer: "Don't Let It Get You Down")
2005 The Puffy Chair (writer: "The Way We Get By")
2004 Mean Creek (writer: "The Way We Get By")
2003 Dumb and Dumberer: When Harry Met Lloyd (writer: "You Gotta Feel It")
2003 A Guy Thing (writer: "You Gotta Feel It")
2001 Summer Catch (writer: "Every Time She Walks")
-- \"The Irritation Man\"