[html]
.box {
-moz-border-radius: 15px;
-webkit-border-radius: 15px;
border-radius: 15px;
-moz-box-shadow: 10px 10px 20px #000;
-webkit-box-shadow: 10px 10px 20px #000;
box-shadow: 10px 10px 20px #000;
}
[/html]
-moz- –> firefox 1.0
-webkit- –> safari 0.2 and chrome 3.0
border-radius –> opera 10.5, IE9, Firefox, Chrome
more detail in developer.mozilla