Works within Stylish, too. I wasn't sure so I gave it a shot and appended it to a style I use for BG and magically there were sigs. Creates a more narrow reading area for wide-monitors when full-screened if anyone wants:

Code:
/* BlueGartr.com - Fixed width centered edited from script by Avgust*/

@namespace url(http://www.w3.org/1999/xhtml);
@-moz-document domain("bluegartr.com")

{
body 
{
float: left;
max-width: 1050px !important;
margin-left: 50px !important;

}
#overlay
{
width: 100% !important;
}
 .signature { max-height: none ! important; }


}