Do you need full ATX or will micro ATX do? If micro will do, then the Ultra Micro Fly will do (from TigerDirect et al.). If ATX, then there are still some Antec Super LanBoy out there (at least Froogle still finds some - but could all be sucker bait). XOxide has some aluminum ChenMing that are basically the same as the original LanBoy and Rosewill has the RZS series.
Oh, and the C-M Mystique 631 I have in my thread in the FS/T section is pretty light for a standard ATX size case. Link below.
.b h.