break. One usecase: you have loops nested 3 deep, and you want to end it all when you find something. You label the outermost loop "exit", and then say "break exit;"
I think continue can use labels, too. (EDITED)
Forgive me but this is going to be a bit off topic. I think it's considered poor taste when a hacker decides to utilize nested loops 3 levels deep.
Sometimes you might have no other choice? I think there are more important things to worry about than this.
I consider it poor taste when a hacker uses a loop (other than a tail call). Nesting is irrelevant.