Few extensions for Chrome Browser:
Opinion Cloud: Summarizes comments on YouTube videos and Flickr photos to provide an overview of the crowd’s overall opinion.
Google Voice: All sorts of helpful Voice features directly from the browser. See how many messages you have, initiate calls and texts, or call numbers on a site by clicking on them.
AutoPager. Automatically loads the next page of a site. You can just scroll down instead of having to click to the next page.
Turn Off the Lights: Fades the page to improve the video-watching experience.
Google Dictionary: Double-click any word to see its definition, or click on the icon in the address bar to look up any word.
After the Deadline: Checks spelling, style, and grammar on your emails, blog, tweets, etc.
Invisible Hand: Does a quick price check and lets you know if the product you are looking at is available at a lower price elsewhere.
Secbrowsing: Checks that your plug-ins (e.g. Java, Flash) are up to date.
Taken from Google Blog with Thanks.