"That's what she said." While it may be uttered any time innuendo presents itself, its origins are unknown. Thomas Lennon and Megan Mullally teamed up to finally give credit where credit's due.
Apparently the famous line can be traced back to a promiscuous girl at Long Beach City College. Played by Megan Mullally, she explains how she achieved local celebrity status, only to be undermined by Mike Myers. Since then, her life has become "too hard and painful"...well, you know how that ends.