Firefox 4.0 was just released on March 22nd. Primary updates in this version include improvements in the browser’s performance, standards support, and an updated user interface — from obvious ones like tab placement and functionality and a dynamically changing stop/refresh/home button to less noticeable ones like better HTML5 and JavaScript support. Along with these comes a redesigned extension manager, and developers have already released a slew of add-ons compatible with the new version. Here are the top five  new Firefox 4 add-ons to try:

DragIt

DragIt (formerly Drag de Go) is a drag-and-drop feature extension for Firefox that allows you to quickly save images on a webpage. All you have to do is drag the text or image item up, down, left or right for it to be saved into a repository. This is perfect for anyone who does a lot of sharing or content creation, and is a lot more convenient than copying and pasting.

Updated: March 24, 2011
Works with: Firefox 4.0
Rating: 4 Stars
Downloads: 60,639

F1 by Mozilla Labs

F1 is a browser extension built by Mozilla itself. It allows you to easily share links to Twitter, Facebook and over Gmail, customizing the browser any way you’d like. All you have to do is type what message you’d like to share with the link. If you’re more of a quick social sharer than a consumer this addon will be great for you — especially if the columns and search features offered by platforms like TweetDeck and Seesmic are too intense for you.

Updated: March 24, 2011
Works with: Firefox 4.0
Rating: 3 Stars
Downloads: 83, 439

FabTabs

The FabTabs Firefox 4 addon will color your browser tabs. Each color is selected based on the color that appears most frequently on that particular web page. This extension will undoubtedly color your browser happy, making it easier for you to remember which tab is which. Many Firefox themes that color your browser often make it difficult to even read the tabs, but FabTabs offers the colors without being so in-your-face.

Updated: March 4, 2011
Works with: Firefox 4.0
Rating: 4 Stars
Downloads: 186,575

Tab Badge

This Mozilla extension adds an alert badge to your browser tabs, alerting you when there’s a new message – be it a new tweet on Twitter or new Facebook message. This add-on helps you see what’s new. If you are a perpetual refresher (and if you can resist being distracted to check out what’s new every time your tab badges changes), this Firefox 4 extension will help a lot.

Updated: March 26, 2011
Works with: Firefox 4.0
Rating: 4 Stars
Downloads: 16,465

Vertical Toolbar

This extension adds a vertical toolbar to the edge of your browser window, either on the left or right. You can customize this toolbar, with automatic hiding and button options, to fit your ideal usage. With tabs now placed above the search bar on Firefox 4, this addon will further maximize your screen’s height.

Updated: March 27, 2011
Works with: Firefox 4.0
Rating: 4 Stars
Downloads: 28,888

What other add-ons would you recommend for Firefox 4?