Mozilla has touted Firefox 3 as faster and more secure than earlier versions of the open-source web browser. But there's another reason to look at the browser upgrade: it is highly customizable for individual users by utilizing the massive library of Add-ons - additional features that users can choose to install on top of the browser.

With that in mind, we examined three Add-Ons for Firefox 3 that can help you interact with colleagues and browse the web more efficiently to find the relevant content you need for your job. In some ways, the overall usefulness of an add-on can be measured by its ability to help the user without opening more tabs, and these add-ons seem to do that well.

An additional two Add-Ons help the overall user interface (which, even with just the out-of-the box download, is prettier that the last Firefox).

1. LinkedIn Companion For Firefox 3.1.1

So far, a prominent way to connect with colleagues and friends in the professional world is through LinkedIn, the online social network for business contacts. The LinkedIn Companion is an add-on that allows you to utilize your connections on LinkedIn in other applications (such as Gmail and Yahoo mail) without having to keep LinkedIn open as a tab on your Web-browser.

For instance, if you open an email in Gmail from your friend John, a small blue and white logo (LinkedIn's colors) that says "info" will appear next to that person's name. If you scroll your mouse over it, you will have a link that can take you to that person's LinkedIn profile. It will also show you how many connections you share in your geographical area, based on the information LinkedIn members provide.

2. Google Preview

When you forget to bookmark a page, you probably turn to Google and search for it. But when you get to the results page, sometimes it's hard to remember which one you clicked on. (Sometimes the browser will change the color of the link, but not always). With Google Preview, you can see a small version of the web-page that the link will lead you to, which should help jar your memory and avoid the need to click on several results to see which one you picked last time.

3. TwitterFox

Twitter, a social networking service that asks users "What are you doing" in 140 characters or less, is a good way to keep track of colleagues, friends, and even customers. While some updates people make center around the mundane ("Going to the store"), some can be quite interesting ("Considering making x type of product. What do you think?").With TwitterFox, you can let this information feed to your browser without it being too disruptive.

After installation, a small "T" resides in the corner. When a number appears next to it (say "1"), you know some of your friends have posted a "tweet" (a message on Twitter). The number increases as more unread messages compile. You can click on the box when you want to see what they've written. There is also an option to let their messages pop up for a few seconds in the corner above the T.