Demo using CSS to create a sleight of hand effect

body {background: black url(shell-bg.jpg) 0 0 no-repeat fixed;}
div#content {background: #468 url(shell-blue.jpg) 0 0 no-repeat fixed;}
div#links a {
background: transparent url(shell-fade.jpg)
0 0 no-repeat fixed;
}
div#links a:hover {
background: transparent url(shell-wash.jpg)
0 0 no-repeat fixed;
}