Shareaholic is the easiest way to share & bookmark great content from anywhere on the web from one simple ALL-IN-ONE add-on. Works with Facebook, Twitter, Pinterest, Google, LinkedIn, E-mail and 200+ additional services.
Official eBay add-on. Keep an eye on your eBay activity wherever you are on the web when you install the eBay Sidebar for Firefox. It’s a free tool built with eBay users in mind that will help you get more out of your buying and selling on eBay.
Automatically get the lowest price on whatever you’re buying
Comparison shop for the best fares on airline websites. Yapta will track fares for the flights you like and notify you when prices drop.