Anything that can prevent the need to do more copying and pasting is fine by me. Hyperwords does exactly that allowing you to search, spell check and translate with a simple right click.
Hyperwords is an extension which installs itself into your Cmd-click or right-click context menu. Just select any word or phrase in some text and a menu appears, containing searches, references, blogging, emailing, copying, translation, and more in a single click. There are several main options - Search, Reference, Shop, Share, Copy, Translate and View.
Within these, are several sub-options that allow you to search Wikipedia, Amazon, translate the text, share on Facebook and Twitter and much more. It's a wonderful extension for anyone who needs instant access to Twitter, shopping sites and translation sites without leaving the web page they are on. Perhaps the only downside is that the menu can be a little obtrusive when trying to access other elements in the context menu and sometimes slows down the speed at which the menu appears.
Hyperwords is an excellent Firefox extension that will soon have you wondering how you lived without it.