Superman is a fictional DC Comics superhero. In 2003, Colonel Jack O'Neill asked the People of P3X-367 if anyone of them was "more powerful than a locomotive." This comes from the phrase "faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound" that was used to describe Superman. (SG1: "Metamorphosis")
When trying to protect Atlantis from the Lantean storm in 2004, Dr. Rodney McKay told Major John Sheppard that he is not Superman. (SGA: "The Storm")
When trapped in a Time dilation field on the Odyssey in 2007, Lt. Colonel Cameron Mitchell said "See what we need is, we need Superman to fly around the ship really, really fast." (SG1: "Unending")