I would like to request that similar functionality be implemented into WebKit.
(Side note: This is my first feature request. If I am submitting it incorrectly, please let me know.)
Created attachment 104061 [details]
This is what the feature in Firebug looks like.
*** This bug has been marked as a duplicate of bug 128795 ***
*** This bug has been marked as a duplicate of bug 128785 ***