ClickCutter is a free firefox addon which allows you to copy paste any text in firefox just by highlighting the text on any webpage, this way you can quickly copy text with out even right clicking the mouse and then select copy text. You have full control of what to copy and what not to copy when you highlight text,
you can use the middle mouse button to Paste.
Unlike other ‘autocopy’ extensions with ClickCutter AutoCopy you can Copy only text you need. Avoid frustrations with unwanted copying when editing your text with operations such as replacing, moving, deleting or printing selected text. You highlight text and you decide if you want to copy it clipboard. All with a special command with your mouse without any additional mouse clicks.
Note: ClickCutter is also available for windows but it is not free for windows you will need to buy, but is completely free addon in firefox works with text, web forms, search and address bars
Install ClickCutter For Firefox