Found an interesting article on why you shouldn’t remove that rather unsightly dotted border around anchor links. The border which only appears when a link is clicked is not a bug or styling error – it’s actually an important accessibility feature for keyboard users. While it’s easy to remove simply by adding a { outline:0; } to your stylesheet, the article explains why it’s better not to remove it and how to deal with it.

http://haslayout.net/css-tuts/Removing-Dotted-Border-on-Clicked-Links