In season two, the decreased presence of the character Elizabeth Burke, and conspicuous green-screen scenes, was due to the pregnancy of her actress, Tiffani Thiessen.
Inspired by the exploits of Frank Abagnale Jr who was once a counterfeiter and confidence trickster who ended up working for the FBI
Charles Dickens references: In the episode "Upper West Side story", where the class is studying "A Tale of Two Cities," Mozzie introduces himself to Evan as Professor Magwitch. Mozzie also often uses the alias "Havisham." Both are names of characters in Great Expectations.
Matt Bomer loves to sing and he would sing songs to get them stuck in the heads of the other cast members. In a Paly Center interview Tim Dekay said that one song would be Total Eclipse of the Heart because the cameramen would tell the actors they were turning around to get a shot of another person and that would make them think of the lyrics to the song.
One of Neal's aliases is Nick Halden. This is a reference to the name of Tony Curtis' character in the movie "Operation Petticoat"