In Back to te Future when Marty McFly's band is auditioning to play the prom, they're playing a cover of "The Power of Love" by Huey Lewis. The committee chair that says, "you're just too darn loud" is none other than Huey Lewis, himself!
I also loved Patrick Stewart's hilarious cameo in "L.A. Story". His much shorter appearance in "Robin Hood: Men In Tights" was cute too. Other previously mentioned cameos that I enjoyed were the Charlton Heston cameo in Wayne's World 2, and the other cartoon characters in "Who Framed Roger Rabbit". It was nice to see Mickey Mouse, Donald Duck, and Daffy Duck in that movie, and it makes me happy to know that the movie gave Mel Blanc the chance to do the voice of a Looney Tunes character in at least one theatrical feature. The cameo appearance of Sesame Street characters at the wedding in "The Muppets Take Manhattan" made me happy too.
No, you're actually incorrect. "Jackie Brown" was released in '97 and "Out of Sight" was in '98.
"Out of Sight" wasn't released until 7 months after "Jackie Brown", so they were released pretty close but there's no denying that Keaton did "JB" first. It was the Weinsteins that let Universal use the character for free, I doubt it would have worked the other way around.