The Japanese have a whole series of series, in manga and anime, involving giant robots (or mecha, as most of these are not actually autonomous but have human pilots; either remote, or more often in a cockpit in the head area).
One such is The Big O (1999 TV Series), in which Roger Smith (the Negotiator) summons and pilots a skyscraper-size behemoth against various other monsters, most of whom are also mechanical in nature.
When he fires up Big O, the boot sequence shown on the screen is ...
"CAST IN THE NAME OF GOD, YE NOT GUILTY".
Where did that come from?
Series director Kazuyoshi Katayama had read a magazine article about John Milius and his 1982 movie "Conan the Barbarian". The opening title sequence of that movie shows Conan's father casting, forging and tempering his own sword. Engraved on the blade, in Runic characters, was "Suffer no guilt ye who wields this in the name of Crom": a variation of phrases sometimes engraved on the swords of executioners in the 17th century. Katayama liked it and incorporated it into the series.
Another staple in Japanese manga and anime are kaiju.
That word is often taken as meaning "giant beast", but its literal translation is "strange beast" and usually refers to a bunch of Japanese films featuring such; Godzilla (1954) being the archetype ...
The name "Godzilla" is a romanization, by the film production company Toho Company Ltd., of the original Japanese name "Gojira" — which is a combination of two Japanese words: gorira (gorilla) and kujira (whale). The word alludes to the size, power and aquatic origin of Godzilla.
And now, get ready for a live-action incorporation of mecha and kaiju.
From director Guillermo del Toro (The Devil's Backbone (2001), Hellboy (2004), Pan's Labyrinth (2006) ) comes ...
... Pacific Rim (2013), due to open 12 Jul 2013.
When Earth is threatened by kaiju (one source says released from a crevice in the Pacific, another implies that they are the tools/weapons of aliens), we construct giant robots/mecha (called Jaegers; from the German word for "hunter"; pronounced "Yeager"), with which to fight them.
I was bitterly disappointed at the news, last January, that Universal had pulled the plug on del Toro's project to bring H.P. Lovecraft's "At the Mountains of Madness" to the screen ("Hellboy" had some scenes that were positively Lovecraftian, suggesting that he could do an excellent job there). I understand that he has not given up on the project, and it may eventually happen someday.
But, in the meantime, he's concentrated on "Pacific Rim".
Giant robots fighting giant monsters? From a practical point of view, that might be the only thing they would actually be good for. While cool as Hell, I suspect that what amounts to a walking destroyer would make a truly awesome target in a real war.
But, I expect to be first in line when this opens. :-)