If you're a Firefox user, chances are you've been using add-ons to extend its functionality. But if you haven't, or if you're looking for new add-ons, I've found 20 for you to try. But since installing all 20 will probably slow your browser to a crawl, I've broken them into four categories. I have grouped the add-ons into "packs" for business professionals, shoppers, social-network fanatics, and students.
The business professional
Xmarks (download): If you're running a business and want everyone in the office to have the same resources available to them, Xmarks is the way to do it. Simply download it into your browser, create an account, and install it on all the browsers in the office. Once configured, every Xmarks instance connected to that account will be automatically updated whenever a user adds a bookmark. In other words, if one employee adds Webware to their bookmarks, every other person in the office who's running Xmarks will have it installed, as well.
Jigsaw Contact and Company Search: Most business professionals need to have easy access to a company's contact information. If you're one of those people, consider using the Jigsaw Contact and Company Search. Jigsaw, a global online business directory, features millions of contacts and company profiles that can be searched by title, geography, and business.
Stock Pilot (download): Sometimes going to Google Finance is too time consuming to get quick public company info. Try using Stock Pilot instead. The add-on allows you to switch between financial sites to research a particular stock. It also boasts RSS alerts to update you when news breaks about a company you're tracking. Ready access to SEC filings makes it a handy tool for anyone who wants to see a company's quarterly or annual financial data.
TripSync: Once you install the TripSync travel manager add-on, you'll be blown away by its functionality. You can book and hold reservations to places across the world, receive travel alerts, and place your itineraries on Outlook and Google Calendar. TripSync is designed specifically for the business professional, so it's a bit more useful than using a site like Expedia.
WOT (download): WOT, short for Web of Trust, is designed to ensure security and privacy are maintained while you're browsing. Once installed, the add-on warns you about risky Web sites. It also alerts you to sites that deliver malware or send spam. The add-on shows you safety ratings on over 21 million sites.
1 Stop travel and retail shopping engine: If you want to find the best deals across the U.S., Europe, or Canada, the 1 Stop travel and retail shopping engine add-on is a good place to start. While you're browsing, it allows you to search for flights on more than 40 airlines. It also lets you search for deals on more than 20 sites, including Amazon, eBay, and Wal-Mart. Once you start searching in the add-on, it finds the desired page and automatically opens it in a separate tab.
Buy it online (download): If you've ever been on a Web site and found a product you'd like to buy, but were forced to go to Amazon.com to search for it, you'll be happy to know that there's an add-on designed specifically for you. Dubbed "Buy it online," the add-on adds another option when you right-click on a product title on any Web page. If you click the "Buy it online!" button, you'll be shown a listing of all the stores on the Web that are currently selling the product. All the retailers listed are well-known and trustworthy.
eBayBuddy (download): If you're obsessed with eBay, there's a great add-on you might want to consider. Dubbed eBayBuddy, the tool is available in the right-click menu in Firefox and allows you to have full access to eBay's site map, search, and more. It's a great way to quickly and easily find products on eBay without being forced to deal with the site itself.
KeepCash Coupon Notifier (download): As someone who frequents coupon sites and goes to a retailer's page with the discount ready to be used, I found KeepCash Coupon Notifier to be an extremely useful add-on. Whenever you go to a retail site, it automatically searches its database to find any coupons currently available for the site you're on. If there are, it will list them for you to be used while you're shopping.
PriceAdvance (download): When you run PriceAdvance and surf to a retail site to research a product, the add-on will tell you its price on a handful of other prominent sites across the Web. For instance, if you're on Amazon looking to buy an Xbox 360, the site will automatically search for other retailers selling the console and display their pricing, so you can be sure that you're getting the best price.… Read more