I assume you mean like the left hand menu on this site: http://www.damnwitty.com
That uses the House menu from Tim rolands.
The skin.ascx has the following:
<dnn:HOUSEMENU runat="server" ID="dnnHOUSEMENU" Scope="-1" ShowAdmin="True" IsRecursive="True" Orientation="H" Mode="S" CssElementId="vertmenu" />
and the css is:
#vertmenu {
font-family: Verdana, Arial, Helvetica, sans-serif;
font-size: 100%;
width: 160px;
padding: 0px;
margin: 0px;
}
#vertmenu ul {
list-style: none;
margin: 0px;
padding: 0px;
border: none;
}
#vertmenu ul li {
margin: 0px;
padding: 0px;
}
#vertmenu ul li ul {
margin: 0px;
padding: 0px;
padding-left: 5px;
}
#vertmenu ul li a {
font-size: 90%;
display: block;
border-bottom:1px solid #dadada;
padding: 5px 0px 2px 4px;
text-decoration: none;
color: #4088b8;
width:160px;
}
#vertmenu ul li ul li a {
width:155px;
}
#vertmenu ul li a:hover, #vertmenu ul li a:focus, #vertmenu ul li a#vertmenuCurrentLink {
color: #000000;
background-color: #eeeeee;
}