Zemanta
Zemanta is a tool that looks over your shoulder while you blog and gives you tips and advice suggests related content and pictures and makes sure your posts get promoted as they deserve to be.
HappyFace
HappyFace hides visual distractions on Facebook, allows you to rotate photos, and gives you an attractive design with floating menus.
OneTrueFan
OneTrueFan lets you check in on the web and play to become the biggest fan of your favorite sites. You can see who surfs the same pages as you and discover great new content.
Preview for Blogger
This extension gives you an immediate preview of your writing entry on Google Blogger and expands the input box of Labels.This extension works under the mode Edit HTML only.
Facebook Ads Blocker
Facebook Ads Blocker blocks not only ads on friends' pages, but all over the site. This extension allows you to block ads without losing Facebook functionality.
Facebook Photo Rotator
This extension allows you to rotate photos on Facebook.
Marginize
Marginize turns websites into venues where visitors can check in and have a conversation. You can see who has commented or tweeted about a web page as you browse, or make comments and send them to Facebook, Twitter or Google Buzz.
Shellfish
Use Shellfish to remove sharing buttons for Digg, Delicious, Twitter and other social networking websites, so you don't have to see extra icons on blog posts and news articles.
Blog It
Blog It is an official extension for TypePad that lets you quickly post articles, photos, video, and more to your blog, right from the Safari toolbar. Just click the Blog It button, customize your post, and publish.
SocialPlus!
Add functions to Facebook such as photo zoom, emoticons, Wall filters, rating buttons, an "I don't like" button, and skins to customize the appearance of Facebook.
Facebook Improved
This extension replaces fonts on Facebook with Helvetica. It also blocks the Events module and sponsored content, and ensures you always know where you're posting.
ReadableFacebook
Readable Facebook removes content such as advertising and the "People You May Know" box from Facebook.com.
FacebookBlocker
With FacebookBlocker, you can choose not to see "Like" buttons, "Recommended" lists, and "Most Popular on Facebook" content on sites other than Facebook itself. It even prevents Facebook content within iframes from appearing.
Better Facebook
Better Facebook improves your Facebook experience. Customize your news feed with advanced filters that can hide posts you've read, alert you to new comments, notify you when you've been "unfriended," and more.
Defacer
When you visit websites other than Facebook, Defacer can hide Facebook buttons such as "Like," "Recommend," and "Share." Defacer also hides Facebook content that appears in iframes.
Facebook Cleaner
Facebook Cleaner hides visual distractions — like sponsored ads, pokes, and the Get Connected section — from the Facebook website.
Facebook Photo Zoom
Facebook Photo Zoom is a simple extension that integrates directly into Facebook. Just hover over an image — like a profile picture or a photo in an album — and Facebook Photo Zoom enlarges it for you.
Glue
Find your next favorite movie, book, or album. When you visit popular sites like Amazon, IMDb, and Wikipedia, Glue will appear on the page to show you books, movies, and music that you might like. Suggestions are based on what you like, what your friends like, and what's popular around the web. You can also share links with your Facebook and Twitter friends.
Reddit Comments
Quickly jump to the Reddit comments for the page you're currently viewing. If there are no comments, Reddit Comments starts the submission process and completes the page information for you.
ScribeFire
ScribeFire is a full-featured blog editor that integrates with Safari and lets you easily post to all of your blogs.
Shut Up
Shut Up — based on the shutup.css custom user stylesheet by Steven Frank — lets you hide and show the comments section on many popular websites.
YourVersion
As you browse the web, the YourVersion Safari extension lets you quickly share any page on Twitter, on Facebook, or via email with one click. If you're a registered YourVersion user, pages you share and bookmark using this extension appear in your account on the YourVersion website.