body:before , body:after {
    content: "";
    position: fixed;
    bottom: -20px;
    left: -10px;
    width: 110%;
    height: 20px;

    -webkit-box-shadow: 0px 0px 20px rgba(0,0,0,.9);
       -moz-box-shadow: 0px 0px 20px rgba(0,0,0,.9);
        -ms-box-shadow: 0px 0px 20px rgba(0,0,0,.9);
         -o-box-shadow: 0px 0px 20px rgba(0,0,0,.9);
            box-shadow: 0px 0px 20px rgba(0,0,0,.9);

    z-index: 100;
}

body:before { /* top shadow */
    top: -20px;
}

body:after { /* bottom shadow */
    bottom: -20px;
}

Beispiel: http://jsfiddle.net/VSU8L/
Quelle: http://playground.genelocklin.com/depth/

ImageAlpha can achieve conversion quality better than Macromedia Adobe Fireworks by employing latest pngquant , pngnq .

del {
    color: #AAAAAA;
}

ins {
    -moz-transform: rotate(15deg) translate(0px, -60%);
    display: inline-block;
    margin-left: -2em;
    text-decoration: none;
}