Together with the Tag Cloud, actually right above it, a search bar is provided: you can click on any Tag in the Cloud and add it to the search bar, then you can edit the search bar text, and finally search it on some of the most common websites you might want to search on (Google, Twitter, Facebook, Quora, Wikipedia).

In addition, this extension adds an entry to your right-click context menu inside Chrome; the new entry is shown only when you have selected some text inside a page, and allows you to search the selected text with one of the search engines above, or to translate it using Google Translate (by default, it sets translation from an automatically determined language to English). All of these options requires literally two mouse clicks, and they all open the new search page in a new tab/window.

You can install it from the [chrome webstore](http://goo.gl/pQHts), read about it [here](http://mlarocca.github.com/01-14-2013/tagcloud.html), or check the source code [here](http://goo.gl/Lrqiq)