In one scene as Gidget's father and mother are waiting for her to return, her mother says to her dad "Who did you expect, Kim Novak?" Her dad had played 'Howard Bevins' in Picnic starring 'Kim Novak'.
James Darren was originally not selected to play Moondoggie because the role required two songs to sing and Darren was not well established as a singer. On his own, he cut a single with the studio's recording subsidiary Colpix Records which charted. Columbia changed their minds and gave him the role despite the fact that he couldn't surf and was a weak swimmer. He became a huge teen idol and subsequently repeated the Moondoggie role in Gidget Goes Hawaiian (1961) and Gidget Goes to Rome (1963)with two other Gidgets: Deborah Walley and Cindy Carol.
The producer wanted Elvis Presley to play the leading male role but the studio declined because Presley was at the time too expensive.
The title character was based on the author's daughter, Kathy Kohner-Zuckerman, and her adventures growing up in the surf culture on the beach at Malibu in the 1950's. As of this note (July 2006), she is 62, petite, healthy and attractive and living in Pacific Palisades with her husband of 42 years. And yes, there was a "Moondoggie", who still lives in California and is an artist.