Disney promoted this movie with a series of trailers inserting Stitch into some of its "classic" titles. Examples:
The Little Mermaid (1989): Stitch surfs a wave that crashes down on Ariel.
Beauty and the Beast (1991): Stitch causes the chandelier to fall during the ballroom scene, nearly smashing Belle and the Beast
Aladdin (1992): Stitch steals Princess Jasmine from Aladdin during the "A Whole New World" magic carpet ride.
The Lion King (1994): Stitch takes Simba's place on Pride Rock during the "Circle of Life" opening.

Lilo and Stitch has several references to other Disney movies. A Chinese restaurant that the characters pass is called Mulan Wok, a reference to Disney's Mulan (1998). There is also a poster of Mulan on the wall of Nani's bedroom. Many of the aliens are inspired by Disney characters, including Piglet and Tigger from Winnie the Pooh.
After the success of Lilo and Stitch, Disney released Stitch! The movie in 2003. It tells the story of the other 625 experiments. Another Lilo and Stitch movie will be released on August 30 on DVD, Lilo and Stitch 2 - Stitch has a Glitch.