Oh, and the surround plugin is so useful.. something I tend to do a lot is:

  viws' : viw "highlight the current word" 
          and s' surrounds it with ''. *Soooooo* useful. 
          You can also do yiws' but I like to see what 
          will be surrounded as something there're spaces
          or other characters which doesn't *count* in
          "w".