The most expensive film ever made (at the time), not adjusted for inflation. The budget ran to $300 million. That's more than the budget of all three Lord of the Rings films combined.
The green flash is a real, but very rare, optical phenomenon during sunrise or sunset, that is best observed at sea. It is caused by the refraction of light in the atmosphere, amplified by a mirage.
The character of pirate lord Mistress Ching is likely inspired by the real-life Chinese pirate Cheng I Sao (A.K.A. Ching Yih Saou) who controlled the South China Sea with her large pirate fleet in the early 1800s.
(at around 23 mins) The scene in which Jack the Monkey is shivering was accomplished by the concerted efforts of the special effects and animal training departments. The effects guys made a small wooden barrel with a vibrating plate on top. The animal trainers taught the monkey to sit with her arms crossed on the plate.
A real-life council of pirates existed at one time. The Brethren of the Coast was a loose coalition of pirates and buccaneers, active in the 17th and 18th centuries in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. They had a base on the island of Tortuga, off the coast of Haiti, and in Port Royal, Jamaica. The Brethren were originally French Huguenots and British Protestants, but their ranks were joined by other adventurers of various nationalities, including Spaniards and Africans.
Keith Richards: Playing Captain Teague, Jack Sparrow's father and the keeper of the pirate code. Richards is Johnny Depp's friend and main inspiration for his Jack Sparrow character, and he was slated to appear in Pirates of the Caribbean: Dead Man's Chest (2006), but scheduling conflicts with the world tour of his band The Rolling Stones prevented this. The day Richards came in to film his scenes, he got so drunk on set that Gore Verbinski had to prop him up. Richards remarked, "If you wanted straight, then you got the wrong man."