Outline

When users click links, like this, depending on the browser an outline will be rendered around the link. This is great for accessibility, however graphic intense components of web pages can look poor when user clicks of them, for example navigation bars. To get around this, you can use the following CSS:

a:focus, a:active{
   outline:none;
}

This works in mozilla firefox, and although I haven't checked it should work in opera too.