Almost forgot the Tank Hone, which is a shittier version of the OneGhost. Well, I guess the OneGhost is actually a better version of this, since it's just an updated design. Unsecure image, only https images allowed: http://www.cycletaiwan.com/shop/components/com_virtuemart/shop_image/product/Tank_Hone_frame_48f2e42906bbd.jpg Edit: Just noticed this hombre doesn't have any horizontal dropouts. Gotta find that perfect gear ration.
And here's another tank frame with a concentric pivot, but no horizontal dropouts. Unsecure image, only https images allowed: http://www.cycletaiwan.com/shop/components/com_virtuemart/shop_image/product/Tank_T_Works_fra_4a8e76c8a8f30.jpg