Custom dotjs scripts.
~/.js have jQuery 1.6.2 loaded, regardless of whether the site you're hacking uses jQuery. ~/.js/default.js is loaded on every request, meaning you can stick plugins or helper functions in it.
GreaseMonkey user scripts are great, but you need to publish them somewhere and re-publish after making modifications. With dotjs, just add or edit files in ~/.js.
Plugins can be found here.
Firefox plugin : https://addons.mozilla.org/en-US/firefox/addon/dotjs/ Code : https://github.com/rlr/dotjs-addon https://github.com/defunkt/dotjs https://github.com/glenbot/dotjs-ubuntu