Fade in fade out on image hover using CSS3

When someone hovers over an image it will fade in and then when they unhover it fades back out.
To do this, just add the following code to your style.css file:

img {
    opacity: 0.6;
    transition: opacity 1s ease-in-out;
    -moz-transition: opacity 1s ease-in-out;
    -webkit-transition: opacity 1s ease-in-out;
}
img:hover {
    opacity: 1.0;
    transition: opacity .55s ease-in-out;
    -moz-transition: opacity .55s ease-in-out;
    -webkit-transition: opacity }