Yes, there are a few skins already posted here and there's also a tool posted to help you make your own skins.
http://dl.openhandhelds.org/cgi-bin/wiz.cgi?0,0,0,0,50
There's also Gmenu2x which may interest you.
http://dl.openhandhelds.org/cgi-bin/wiz.cgi?0,0,0,0,7,124