DCHighlighter is a powerful extension for Chrome that lets you highlight a word by double-clicking it anywhere in the browser. Just double-click the word to highlight it, and it will also highlight any other words that occur on the same page.

This feature makes it easy to edit the page quickly, even with the page's source code.

TODO:

Add a toggle to the settings window to disable the extension when no page is selected.

Update:

Added link to Google for searching as word is no longer highlighted.