Centre widthless floats

#buttons{
float:right;
position:relative;
left:-50%;
text-align:left;
}
#buttons ul{
list-style:none;
position:relative;
left:50%;
}

#buttons li{float:left;position:relative;}/* ie needs position:relative here*/

#buttons a{
text-decoration:none;
margin:10px;
background:red;
float:left;
border:2px outset blue;
color:#fff;
padding:2px 5px;
text-align:center;
white-space:nowrap;

}
#buttons a:hover{ border:2px inset blue;color:red;background:#f2f2f2;}
#content{overflow:hidden}/* hide horizontal scrollbar*/

thanks http://www.pmob.co.uk/pob/centred-float.htm