Userscripts.org

Scrobble music videos from YouTube to Last FM. Contains both automatic scrobbling and manual scrobbling.

Forces known sites to use a secure connection. Look at description for the sites that are forced to use a secure connection. And just add any sites you want to use an https connection.

Theme of Twitter for Blip.fm

When you visit a user profile, expands the list of groups under the info, by retrieving all the groups the user is in, and highlights the ones you both joined.

Script removes all the redundant data and fancy buttons from the forum posts and increases text size. It tremendously increases overall readability. It also adds a link-toggle-button to revert all these changes back on the fly.