When I\'m working with CSS, I\'ll often test in a browser - say, Chrome - right click an element, click Inspect Element, and edit the CSS right there. The use of arrow keys
My in-beta-soon product LIVEditor does this exactly.
To let you understand it easily, you can think of Firebug's inspector is embedded into your text editor.
That way you don't have to make the changes manually again in your code editor after you tweaking it using Firebug or Webkit's developer tools.