Director Makes a Cameo, Twice
In Big Daddy, Adam Sandler hussles a guy for Halloween candy for his kid. The guy getting hussled is the director of the film, Dennis Dugan. Dennis Dugan also appears as an actor on TV (in the movie). At some point, Adam Sandler is watching an episode of Columbo. On screen is Dennis Dugan, who was Columbo's side-kick and comic relief in the venerable mystery TV show.
Music Director Gets a Mention
At the end, the state's lawyer is named Ted Castelucci. The director of music for the movie is also named Teddy Castelucci.