There was some talk on planet.debian.org about long entries and how to fold them. Erich suggested using max-height for folding the longer entries and Daniel cooked up a hack for Firefox's userContent.css to achive the same.
pdoFoldToggle bookmarklet can fold entries having a height more than 30em (can be changed by changing the value of maxH variable in the bookmarklet) and also undo the action. Hence the name pdoFoldToggle.
If you like folding the posts on planet debian, go get the bookmarlet and play with it.