Not only was It's a Mad, Mad, Mad, Mad World filmed in Cinerama (the biggest of the widescreen cinema technologies), it also had an all-star cast, with literally dozens of major comedy stars from all eras of cinema making appearances in the film.
Stars of this film included:
Kramer claimed he wanted to make the ultimate comedy film. At more than two and a half hours (originally including an intermission) it is certainly one of the longest. Most of the humor is not especially sophisticated, consisting mainly of very noisy slapstick gags. Terry-Thomas's character's rant against the American obsession with bosoms still strikes a chord with non-American audiences.
The New Avengers episode "The Tale of the Big Why" seems to have borrowed part of its storyline from IAMMMMW - at the end of the episode the characters realise they are looking not for a metaphysical "big why" but a physical "big Y".
Rat Race, a film made in 2001, has a similar basic premise.