The Danza: Scott "Scotty" Thomas is played by Scott Mechlowicz
Dawson Casting: Of the 4 main actors only Michelle Trachtenberg was still a teenager — even Kristin Kreuk was in her 20's playing a 16-17 year old. Even Jessica Boehrs, who played Mieke, was in her 20's.
Hey, It's That Guy!: See Lana Lang as an upfront two-timing slut. Buffy's little sister is also in this movie. To say nothing of Jason Bourne as a musician (responsible for belting out "Scotty Doesn't Know"), and Xena, Warrior Princess as a Dutch dominatrix.
In the original script (found on the DVD), there was a character named Adam Lane, the class valedictorian and Cooper's favorite Butt Monkey (he refers to Adam as "Adam Lame", and even got other people to call him that), who would tag along with Scotty's group during their trip, and served as their tour guide. Adam also spoke in a fake British accent. In the final version, Adam was cut, and most of his traits (minus the fake British accent) went to Jamie.
Also in the original script, while in Amsterdam, instead of going to Club Vandersexx (as in the theatrical version), Cooper asked for directions to a brothel called "The Secret House", and he did find the secret house. What he didn't know is that he actually went to The Anne Frank House, where he made out with an Anne Frank mannequin, thinking that it was a sex doll.