this gdm is based on simple ubuntu gdm by elusive (http://gnome-look.org/content/show.php/Simple+Ubuntu+GDM?content=95984) except the buttons.
2bg.png background pic is copyright of The Inspirational Gallery. found at deviantart.com by stroink(http://stroink.deviantart.com/art/damask04-62848402). i just recoloured it.
bg.png is from arc-colors-gdm by perfectska04 (http://gnome-look.org/usermanager/search.php?username=perfectska04)
sorry for the worse screenshot quality:(