Recently there have been some comment pages which require horizontal scrolling because of a single comment that was (probably unintentionally) <pre>formatted (eg: http://news.ycombinator.com/item?id=589346). In case you find that annoying, you can use the Firefox extension 'Toggle Word Wrap' (https://addons.mozilla.org/en-US/firefox/addon/2351) to (temporarily) enable word wrapping within <pre> tags also for that page alone. This restores the usual HN look and eliminates the need for scrolling too.

I'm sorry if this is a resubmission or is very well known, I'm submitting this since I personally found it very helpful.