Epic Movie: If the statistics are to be believed, On Stranger Tides would be the most expensive film to be produced with a budget of $378 million. (though part of it is because to cut costs and take advantage of tax benefits, it was mostly shot in the United Kingdom, and the Pound sterling always has a higher exchange rate compared to the dollar) Still cheaper than making the series a Two-Part Trilogy, as the $450 million for both Dead Man's Chest and At World's End grew up to $500 million (reportedly, $300m alone with the the third movie).
Angelica's claim at the end that she is pregnant. Also doubles as a real life Shout-Out to Anne Bonney and Mary Read, two of the most famous female pirates who avoided the death sentence by (claiming at least) to being pregnant.
The Danza: The dwarf pirate Marty is played by Martin Klebba.
Deleted Scene: Scenes were left out of At World's End which establish that, if the captain of the Flying Dutchman has someone to come home to at the end of his ten years, he can vacate the post to another. Leaving this scene on the cutting-room floor strips important Character Development from Tia Dalma, who knowingly condemned Davy Jones to a Fate Worse Than Death by not waiting for him, and Jones himself, whose fury is now more sympathetic. It also downgrades The Stinger from full-on Babies Ever After to a Bittersweet Ending.
An alternate scene of Jack and Elizabeth on the island in Curse of the Black Pearl which hinted at the darker side of Jack's nature after Elizabeth learns that the "grand adventure of the infamous Jack Sparrow" boiled down to him spending three days "lying on a beach drinking rum" had her questioning whether there was any truth to the other stories that gave him his reputation as a bad ass pirate, to which Jack responds by showing her various scars all over his arms and chest and then saying "None at all." Prior to this there was another scene where Elizabeth went for a walk around the island to dry herself off and then chastise Jack for wanting to trade Will for a ship, at which point Jack reveals that he never had any intention of doing any such thing, if only because Will was his ace in the hole.
Dyeing for Your Art: Many of the actors playing pirates have to wear false, rotten teeth, tanning lotion and contacts. Stellan Skarsgård's makeup took four hours to apply in Dead Man's Chest.
The actors were told that The Reveal at the end of Dead Man's Chest would be of a completely different character - Anna Marie, rather than Barbossa - hence their very realistic surprise.
The Black Pearl's crew screaming while rolling in the bone cages.
Will and Elizabeth's reaction to Jack's little "I've got a jar of dirt" song.
Will's reaction to witnessing Elizabeth's kiss of death at the end.
Executive Meddling: Disney execs (and fans of the theme park ride) freaked out on reports that Depp was getting his teeth capped with numerous gold teeth and piercings for what was originally intended to be a "kid friendly, spooky" companion film to the now-forgotten Haunted Mansion movie. Depp's way of handling this was to take out the offending accessories when the Disney handlers complained... and then put them right back on as soon as they walked away.
Saved from Development Hell: Planning for the second film began in June 2004, but by November, the script was still not finished which forced Gore Verbinski to start planning some sequences without it. By January 2005 there was still no script, and with that on top of the rising costs for the film, Disney almost cancelled it. Around this time they started shooting...with the writers on hand, still writing the script. The same happened with the third film. Explains a lot, doesn't it?
Some early concept art shows a few women among the Flying Dutchman's crew, subverting Cute Monster Girl.
Word of God: The creators claim that Will Turner is the best swordsman of the series while Jack Sparrow is actually the worst swordsman of the series, with Norrington and Barbossa evenly matched in terms of swordsmanship (though what Jack lacks in actual talent he makes up for with improvisation and cheating).