Sharepoint Banner

1. Create you banner.jpg and 
   
2. Copy to C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\IMAGES
   
3. Make modification in the core.css as shown below.("C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\LAYOUTS\1033\STYLES\CORE.CSS")

Before Modification:

.ms-globalbreadcrumb{

font-size:8pt;

text-align:right;

background-color:#ebf3ff;

padding:2px 10px 2px 5px;

}

After Modification:

.ms-globalbreadcrumb{

font-size:8pt;

text-align:right;

background-color:#ebf3ff;

background-image:url("/_layouts/images/banner.jpg");

padding:2px 10px 79px 5px;

}