If you use firefox ( and why would not you ) then this is a killer add-on you cant miss. Juice draws information from sources which include Wikipedia, Google News, YouTube and Techcrunch right into its interface for your quick refernce. All you have to do is, highlight the keyword on the page, drag and drop the keyword into juice sidebar. If you find it difficult to do, just drag it slightly and drop.
That's the magic search of juice. However you can also see the google search result just by pressing the search tab. It will show you different results for web, images, news, videos and blog.
You can also bookmark and organize rich content like videos and images discovered by juice. For example, when Juice comes up with a video as a search result, you can simply add the video into your personal video playlist – for current or future viewing. You can also do this with the videos and images you discover yourself while browsing the web, by dragging the image or tab attached to the videos.
Juice is currently available for only firefox 3 and above and you can download it from here (463 Kb).