Xmarks (formerly FoxMarks)

Maybe you’re only of the few folks remaining that only using 1 computer in your entire day. But for everyone else, Xmarks is a lifesaver. After you’ve installed it (you have to create an account for it), Xmarks will sync your bookmarks (favorites for you IE people) on-line. Install it on a second computer, and it’ll sync there too. Now, here’s where the magic happens. Save a site on computer A, and viiola! it saves on computer B. It also has the ability to sync passwords if you so choose. You’re also able to view them online, if you happen to be away from any of your computers and just need to find that link. (Download here)

Adblock Plus

Do you want the option to refinance your mortgage every 30 seconds? How about the secrets of the credit card companies? No? How about just, you know, the information on the page you’re actually going to then, perhaps? As the name implies, Adblock Plus filters out ads, leaving just empty space in it’s place. So refreshing. (Download here)

Google Redesigned

This extension doesn’t really ‘do’ anything, but it makes the world a better place. This add-on changes the general appearance of GMail, Google Contact, Google Reader, and Google Calendar and gives them a much, MUCH, cleaner UI. Makes the buttons easier to access, and gives the whole thing a general makeover. (Download here)

Greasemonkey + Greasefire

This is a 2 for 1. Greasemonkey is an add-on that allows for simple and site-specific scripts to run. Don’t like the new “People Liked” link on Google Reader? There’s a script for that. What Greasefire does is let you know WHAT scripts are available for any given site, with descriptions and user ratings to go along with it. (Download here and here)

Zotero

For folks in school, or otherwise have to research things that, you know, require actual facts, this add-on can be a lifesaver. Zotero collects, stores, and organizes various sources on-line as you research, and gives you the ability to cite them as needed. Esp. great for when you’ve gone 15 links away from where you started, and need to remember what link #7 was (Download here)

So how about you? What other add-ons have become a must-have in your web-based world?