Superman has been cloned a few times before, but it usually occurs due to the influence, assistance or violation of an outside force or being (such as Red Kryptonite). However, he has also spontaneously split in to two people on several occasions under his own power, either voluntarily or otherwise. In the Superman III movie, an emotional breakdown caused him to split in to good and evil versions of himself. A 1952 live action episode of Adventures of Superman saw him split in to two in order to save Lois and a man who were trapped in a Pennsylvania mineshaft. And, of course, it's happened on various occasions in the comic books, such as the occasion illustrated above. On a related note, Superman also once fired a midget version of himself out of the palm of his hand. Yes, really.
