It's mostly something I do after discovering a useful site I'll likely be revisiting in the future, sites with appreciable content but are otherwise marred with

It's mostly something I do after discovering a useful site I'll likely be revisiting in the future, sites with appreciable content but are otherwise marred with poor visuals. When you've been doing it for years revisiting the same sites, I think it pays for itself in terms of delivering more presentable information. Addons for Firefox include Aardvark, (generic) Element Hiding Helpers, Lizard, Nuke Anything. You press whatever shortcut is assigned and highlight the element your cursor is over (or highlighted text/section), an interface pops up, you specify the domain filter (twitter.com), and filter by attribute (import-prompt), OK, and the rule "twitter.com##.import-prompt" now forever hides twitter's annoying import flex module. The addons for Firefox I've seen are mostly GUI-based. An exception is Nuke Anything, which I believe can be done through keyboard and context menu options.