Numerous real life versions of the ball in the film have been made over the years.
For a brief time, Disney made a real life version of Luxo Jr. and included the lamp in a limited collectors edition of Up. They quickly stopped producing them though after Luxo ASA (the company who made the lamp that inspired Luxo Jr.) sued them for copyright infringement, making them a rare collectors item today.
Inspiration for the Work: John Lasseter had a Luxo architect's lamp on his desk at the time. One afternoon, while trying to come up with an idea for a short film, he started playing with the lamp like a puppet and realized that, with the right manipulation, it could make expressive movements despite not having a face.
Word of God: When asked about whether Luxo Sr. was a mother or father, John Lasseter claimed it was a father. He also said that being asked that instead of any technical questions was the greatest compliment and proof that CGI could be used for character animation.
Write What You Know: While he claims that Luxo Sr. is a father, John Lasseter based its personality on his mother, who would always remain calm when he got himself into dangerous situations as a child.
General
First computer-animated short nominated for an Academy Award.
In addition to the title character becoming the studio's mascot, the ball it plays with has made appearances in various Pixar films: it appears twice in Toy Story, where one of Andy's friends dribbles it, and later in the picture where Buzz Lightyear bounces off it as proof he can fly around Andy's room with his eyes closed, once near the end of Monsters, Inc. in Boo's bedroom and once in Up in the bedroom of a little girl that Carl's house flies by.
