Next to the Quidditch Trophy is a "Service to the School" trophy, awarded to one "Tom M. Riddle"
At one point, when Harry, Ron, and Hermione are approaching Hagrid, he can be seen playing a wind instrument. He is playing the Hedwig's Theme.
Alan Rickman was hand-picked to play Snape by J.K. Rowling, and received special instruction from her as to his character. Rowling even provided the actor with vital details of Snape's back story not revealed until the final novel.
Richard Harris only agreed to taking the part of Albus Dumbledore after his eleven year old granddaughter threatened never to speak to him again.
Alan Rickman was hand-picked to play Snape by J.K. Rowling.
Among the portraits on the shifting staircase, you can clearly see a painting of Anne Boleyn, King Henry VIII's second wife and the mother of Queen Elizabeth I. Anne Boleyn was popularly believed to be a witch.
Steven Spielberg was offered the position as director, but was later refused when he couldn't agree with JK Rowling's insistence on an all-British cast. He wanted to use Haley Joel Osment for the part of Harry.
There was a huge media outcry in Gloucester, England when it was decided to use the local Cathedral for some of the Hogwarts scenes. Protesters wrote letters by the sack-load to local newspapers, claiming it was blasphemy and promising to block the film-crew's access. In the end, only one protester turned up.
Robbie Coltrane was the very first person to be cast.
Author J.K. Rowling insisted that the principal cast be British and she got her wish, with two exceptions - Richard Harris was, of course, Irish, and Zoë Wanamaker, though she has made her name as a "British" actress, is actually a US citizen. Other non-Brits in the cast include Verne Troyer, born in Michigan, USA, who plays Griphook (the second Goblin in Gringots' Bank) and Christopher Columbus' daughter, Eleanor, who played Susan Bones.
The movie is known as "Harry Potter and the Philosopher's Stone" everywhere except the USA and so every scene in which the Philosopher's Stone was mentioned was filmed twice, once with the actors saying "Philosopher's" and once with the actors saying "Sorcerer's".