Most Web sites pay their bills using advertisements, which often distract you from seeing anything else on the page.
Originally created for Firefox, AdBlock Plus blocks banners, pop-ups, ads, YouTube video advertisements, and other bothersome images.
Feeling guilty about blocking ads on your favorite Web site (because that's the only way they'll stay afloat)? AdBlock Plus lets you enable advertisements for specific sites.
2: Screen Capture (by Google)
Screen Capture lets you grab entire pages or selected areas and annotate them with highlights, drawings, and borders. Then, quickly save your screenshot, or share directly to Facebook or Picasa.
Simple, convenient, and seriously useful.
3: Read Later Fast
Although it's technically an app (the extension is coming soon), this add-on is too good to pass up.
Anytime you see an article you'd like to read later, right-click the page, select "Read Later," and it'll be added to your queue. When you're ready to catch up on your reading, open the app in your browser, and read the articles in a beautiful interface.
Read Later Fast also syncs you items with other computers, iOS devices, and Android devices.
4: Xmarks Bookmark Sync
Sure, Chrome syncs bookmarks across multiple computers using Chrome, but what if you use multiple browsers?
Xmarks syncs your bookmarks and open tabs across multiple browsers, which is especially helpful if you've decided to switch browsers, or simply use a variety of browsers.
5: Stay Focusd
Let's face it, sites like Facebook and other entertaining places like Reddit and Stumbleupon are extremely distracting--especially when you need to get work done.
If you're noticing a destructive pattern, StayFocusd restricts the amount of time you can spend on addicting Web sites, letting you focus on more important things like work.
There are many customizable options there, too, including adding exceptions for certain days and times.