Adam Sandler, and the film's producer's were almost sued for plagiarism by scholastic inc when the film's plot was revealed and well known. The reason being because in 1995 11 years prior to this film the popular author R.L. Stine wrote a very similar story in his "tales to give you goosebumps" with almost the exact same plot and setup as this film...even down to both being titled Click, no legal action was ever taken as both agreed to the whole thing being a coincidence.
In the "first kiss flashback", Jennifer Coolidge's character is seen wearing a Simpsons shirt. Julie Kavner (Trudy Newman, Michael's mom) provides the voice for Marge Simpson in "The Simpsons" franchise.
Michael passes on a favor from Mr. Ammer, to which Mr. Ammer replies, "I'll put Swardson on it." Nick Swardson is a friend of Adam Sandler, appearing on Sandler's most recent comedy album, "Shh... Don't Tell" (2004). Swardson is also the Bed, Bath & Beyond Guy who asks Michael to be his friend.
Several future world events are mentioned by radio in the film as Michael fast-forwards through his life. Two of these include Michael Jackson becoming the first human to clone himself and Britney Spears having her 23rd baby. The dates the film is set in the future span from 2017 to 2030.
In the DVD Audio commentary, director Frank Coraci states that the scene set in the past where Adam Sandler and Kate Beckinsale's characters kiss for the first time was deliberately over light to look like a late 80s/early 90s film.
The film's premise was originated from a joke by writer Steve Koren. It was only upon a suggestion of turning into a feature, by the girlfriend of co-writer Mark O'Keefe, that the project got started off the ground.