At the end of this episode, CGIS Special Agent Borin says to Gibbs, "Semper Fi." Gibbs then replies, "Semper Paratus." Most people will recognize Semper Fi (Semper Fidelis) as the motto of the United States Marine Corps. Semper Paratus is the less well known motto of the United States Coast Guard.
The beeping device that's used to prank Ducky is said in the episode to be a "ThinkGeek Annoy-o-Tron", which is an actual device. The day after this episode first aired, ThinkGeek stated that the device was on a two-week backorder.
The USMC motto, Semper Fi (Fidelis) is Latin for "Always Loyal or Faithful". The USCG motto is "Semper Paratus", meaning "Always Ready".