Pretty much all of the browsers support gradients. Here's the CSS you need:
.gradient{
/* For any browser that can't create a gradient */
background-color: #EFEFEF;
/*//mozilla*/
background: -moz-linear-gradient(top, #efefef, #FFF);
/* Chrome/Safari */
background: -webkit-gradient(linear, left top, left bottom, from(#EFEFEF), to(#FFF));
/*IE 6/7 */ filter:progid:DXImageTransform.Microsoft.Gradient(GradientType=0, StartColorStr='#EFEFEF',EndColorStr='#FFF');
/*IE 8 */
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#EFEFEF, endColorstr=#FFF)";
}