Greer made guest appearances on the television series "Just Shoot Me!" (2003), "" (2005), "My Name Is Earl" (2006), "It's Always Sunny in Philadelphia" (2007, 2011), "Californication" (2007–2008, 2012), "ER" (2009), "House" (2009), "Modern Family" (2010), "The Big Bang Theory" (2010), "How I Met Your Mother" (2010), and "Warren the Ape" (2010). She took on a starring role in the ABC sitcom "Miss Guided" (2008), but it was cancelled in its first season. She also starred opposite Zach Galifianakis in the indie satire film "Visioneers" (2008).