oi check it out the gate from full metal looks heaps like this gate
en.wikipedia. org/wiki/Image: Hoellentor.jpg
(sorry cant post pics or links yet just get rid of the spaces to use the link)
this gate is some art work that is supposed to be the gates of hell
so probly somethin to do with the humonculus and them being named after the sins.
it has some resemblance... but doesn't the Gate in FMA have the Kabbalah (http://en.wikipedia.org/wiki/Kabbalah) on it ? i don't quite remember.
i think that it is hell's gate thats why it looks simlar to the picture
ya it was the gate to pass to the other world as ether a person or as a soul of the dead