Safariにインストールした機能拡張（Extension, SIMBL）

ClickToPlugin

ClickToPlugin is a lightweight and highly customizable extension that prevents Safari from launching plug-ins automatically, resulting in faster browsing, reduced fan usage, and increased battery life. It replaces every plug-in object by an unobtrusive placeholder that can be clicked to load the embedded content. Further, it can replace many plug-in-based media players by Safari’s native HTML5 media player. ClickToFlash is a restriction of ClickToPlugin that only deals with Flash content.
http://hoyois.github.com/safariextensions/clicktoplugin/

LinkThing

LinkThing is an extension that enhances your control over how links on web pages are opened. If, like me, you obsess over tiny details of your Macintosh browsing experience, you may find LinkThing useful. If not, you’ll probably wonder what’s wrong with me.
http://canisbos.com/linkthing

Safari Cookies

Safari Cookies automatically manage your Cookies, Flash Cookies, Local Storage/Databases from the Safari preferences pane.
http://sweetpproductions.com/safaricookies/index.htm

Glims

Glims adds a cocktail of features to Safari (Tabs, Thumbnails, Full Screen, Search Engines, Search Suggestions, Forms autocomplete on, Dated download folders, Type Ahead ...)
http://www.machangout.com/