e.g., the polygons cfdg, which has quite a few to sift through.
i can't really think of an accurate succint way of describing it, but it's a feature in [textmate], which i've been using for quite a while. only, they call it foldings. a little animation on the front page of [textmate]'s site shows how it works.
basically, there's a little arrow button at the beginning and end of each specified section, and clicking either of them collapses it down to one line. clicking the button again expands it out, if you need to edit/examine the contents. hovering over a section title shows you some/all of the code hidden therein.
it's a great idea, and it makes for very, very clean files.
gimmegimmegimme (please?
)