Something I just noticed
According to IMDb, "Gidget" was released on April 10, 1959, yet near the end of the film, when Moondoggie finds Kahuna's new employee ID card, it distinctly says "Start date: September 15, 1959". (I assume the film ends just before Labour Day.) So, any viewers who saw "Gidget" when it first came out would have seen a movie set at least a few months in the future! :-)
On another subject, was anyone else bothered by Gidget's reaction when Moondoggie asks if she will wear his frat pin? Almost the first thing she says is "Wait till the other girls get a load of this!", as if the status of having an official boyfriend means considerably more to her than the guy himself!