Twitter Search - is a FireFox extension that enables you to search content on Twitter web site. This extension even looks into the tweets left by other Twitter users. You can find people on Twitter using this FireFox extension. A Twitter search engine loads into the search engine list on the FireFox web browser.
Power Twitter - adds many features to your Twitter Web interface like you can narrow your search to a specific user on Twitter, Facebook updates, it allows URL expansion, you can do custom settings to Twitter, you can even upload photos, you can include other media sites like YouTube, Flickr, Google Maps and many more.
StockTwits - allows you to search and follow the stocks you like. It displays tweets related to that stocks you have selected from the Twitter Web site. This is really useful if you are doing online trading and want to know up to date information on the stocks you follow.
Twitter Fox - is the most loved FireFox extension for Twitter. This FireFox extension keeps you updated about your friends on Twitter. If your friends update their tweets, it immediately notifies you about that. Also, you can update your own tweets with the help of text input field present in Twitter Fox. This FireFox extension is known as TwitterNotifier earlier.
TwitterBar - allows you to post tweets from your browser address bar. You can enter up-to 140 characters. After installing this addon to FireFox, a small Twitter icon will appear to the right hand side of the address bar. You can type your tweet in the address bar and click on the Twitter icon to post your tweet. You can see how many characters are left by pointing the icon. Click on the Twitter icon to tweet the URL of the website you are currently viewing.
Twitzer - allows you to post tweets more than 140 characters on to Twitter website. You can directly post your tweet to Twitter using this FireFox add-on. It also has an additional feature, which converts and resolves TinyURL links so that you are sure that you click on the safe links and view the target website.
TwitBin - this is like a Twitter messenger. Using this FireFox extension, you can easily send and receive messages from your friends and Twitter via Twitter right from your browser. This is a very cool FireFox extension and every Twitter user must have this extension.
TwitKit - is Twitter sidebar for FireFox. It has 6- section interface. You can use tabs to separate content on the Twitter page. It enables you to view your timeline and Twitter public timeline. You can also view the latest tweets left by your friends and followers. You can view your friends list replies send to you and also view your account stats using TwitKit.
Song.ly - allows you to share music links with your friends. When you come across a music file link and want to share it with your friends, just right click on the link and select ‘Song.ly: Share this song’ from the context menu. Now your friends will get the link of the music file, which you have shared with them they can listen to the music right from the browser.
TwittyTunes - allows you to post the list of songs that you are currently playing to the Twitter website. You can also post the URL of the websites that you are viewing, videos that you are watching and many more. You can post URL or play-lists just in one click.
[Via : quickonlinetips ]