Another example of the power and usefulness of continuations comes from pg, who wrote years ago that a key reason why Viaweb was routinely able to launch new features faster than the competition back in the 1990's is because they wrote their code in continuation-passing style -- they were generating closures on the fly that would be called when users clicked on specific links on web pages, whereas the competition was using HTML pages with CGI scripts:

http://ep.yimg.com/ty/cdn/paulgraham/bbnexcerpts.txt