Code examples from Visual Stylin' with CSS3 by Charles Wyke-Smith

Section 5 • Box Shadows

box-shadow: 8px 8px #000;
box-shadow: 8px 8px 4px #AAA;
box-shadow: 12px 12px 40px #AAA;
Figure 50: Three basic shadows.
box-shadow: -8px -8px 4px #AAA;
box-shadow: 0px 0px 20px 4px #F99;
box-shadow: -10px -10px 10px #CCC inset, 10px 10px 10px #FFF inset; background:#EEE;
Figure 51: Three variations of more complex shadow effects.
box-shadow: 0 5px 5px 4px #DDD;
box-shadow: 0 -8px 8px -1px #999;
box-shadow: 0 12px 8px -9px #555;
Figure 52: Three variations of single border shadows.
height:100px;
width:150px;
background-color:#CC3300;
border:4px dashed #FFF;
border-radius:10px;
box-shadow: 
4px 4px #C30,	/* four hard shadows extend the box */
-4px 4px #C30, 
4px -4px #C30,
-4px -4px #C30, 
8px 8px 12px #AAA; /* 'real' shadow */
Figure 53: Four hard-edged shadows extend the box past its dashed border, creating the popular stitched effect.