Lots of heroes have powers they only use once, and Superman is certainly the king of that entire phenomenon. The tough part is, Superman has so many powers that it's hard to tell where a totally new power kicks in, and a new use or permutation of superstrength and superspeed take over. Add to this writers like Cary Bates, who must have sworn on a Bible somewhere to have a different use for superspeed and superstrength every issue FOR YEARS.
Superman also has several minor powers that are only occasionally hinted at: Super-Shouts, Super-Hypnotism, Super-Sensitive Nostrils, Super-Aim. and so on. There was one story that was mentioned in the index that had Superman actually control the muscles of his face to resemble another person. This was dropped, hopefully because it was a straight swipe from the pulp hero the Avenger, and they probably justly felt guilty about it.
The section on Superman's Powers on this website contains some of the crazier stuff, but here's a few things nobody mentions:
SUPERMAN'S SUPER-STRETCHY CAPE.I don't remember the issue number, but it was a story about a kid whose "Superman Games" prevented Superman from using his "real" powers. In this story, Superman saves a town from flooding by stretching his big red cape over...the ENTIRE town.
UNTRANSFORMABILITYSuperman's invulnerability is such that any time a foe causes Supeman to change shape, like the Youth Serum from "The Five Legion Orphans" or the Gas Trap spell of Ghast in JUSTICE LEAGUE OF AMERICA #11 (1962) we can thus assume that Superman has resistance to any type of attack meant to transform or cause him to change shape against his will, possibly as a property of his invulnerability.
SUPER-BALANCEIs it possible that Superman's supreme ability to determine balance may be related to his super-hearing, as is the case with Daredevil?
SUPER-SENSITIVE TOUCHI can't remember the issue, but I do remember that Superman could use his sense of touch in Daredevil-esque ways, to read a paper by feeling the grooves of ink, and listening in to phone conversations by holding the intervening wire.
NIGHT-VISIONSuperman, during the Adult Legion Story and elsewhere, states that he can see perfectly well in the dark. Arguably, this is a totally seperate power.
VISION POWERS DOING INSANE THINGSTechnically, these should count as strange permutations of existing powers, but they're absolutely worth mentioning because of how crazy the uses are for what are essentially, passive powers. I swear, it wouldn't surprise me if there's an issue somewhere that Superman uses his Telescopic Vision to bring back the dead. There was an issue of Superboy where he used X-Rays to make plants grow. In an issue of JUSTICE LEAGUE OF AMERICA, notorious for not really having a handle on Superman's powers, once used Superman's Telescopic Vision to see into other dimensions.
OTHER SUPERHEROES/VILLAINS WITH RARELY-USED POWERS:
THE INVISIBLE WOMAN. Sue Storm has a rarely used ability to make invisible things visible, which she got around the same time as her forcefields. Last time she used this to my knowledge, was in CONTEST OF CHAMPIONS, to reveal the hidden location of the Contest Sphere.
THE WASP. The Wasp had powers in her first appearance involving her now disused antennae that have utterly fallen into limbo forever since (and presumably fallen off as well). This is the best example of an unused power I can think of, because not only has she not used her antennae in decades, they've actually fallen off! I guess they just don't make antennae like they used to.
NAMOR, THE SUB-MARINERThe reason I have exact numbers and what have you for this one is because I was pouring over my back issues, and Namor doing crazy things inspired this post. Namor demonstrated that he could, like the electric eel, absorb and redirect current, a power that has been mentioned a few times since. It was mentioned in several Golden Age comics, and various issues by Roy Thomas, that Namor has eyes that are sensitive to the blue-green portion of the spectrum, giving him greater sight underwater as well as in the dark.
In several FANTASTIC FOUR stories, Ben Grimm says, when trying to grapple Namor, that he is "slippery as a blasted eel!" I don't know...does being slippery count as a superpower? It certainly counts as being weird, that's for sure.
The story where the Avenging Son uses the most strange powers has to be "Suddenly, the Sub Mariner" by Roy Thomas in AVENGERS #40. Here in this story alone, Namor is able to detect underwater signals and follow them to their point of origin. EXACT QUOTE:
"My HYBRID SENSES detect a MESSAGE - which the humans are relaying to their place of ORIGIN!"
"Thus, I will follow this radio beams to their DESTINATION, and DESTROY all craft there..." [/list]
It should be significant to note that radio, to the best of my knowledge, does not work underwater. A possible explanation may be that 1) it was another form of communication and Namor fudged it into "radio," 2) the sub, which was not shown in that particular panel, may have surfaced, making use of the radio possible.
Namor uses another seldom-used power later on in that very issue: Namor is actually able to telepathically command fish and sea creatures, instructing them to conduct a search of the sea floor to find the Cosmic Cube for him. His thought waves are described as being "irresistable mental commands." Maybe Roy the Boy confused Namor with a certain...OTHER fish guy? It should be noted that Roy Thomas wanted the Earth-2 Aquaman to be a regular member of the ALL-STAR SQUADRON before he was outvoted.
DOCTOR DOOM. It was established in a FANTASTIC FOUR arc that Doctor Doom learned the secret of mind transfer from when he spent time among the Ovoid race. The mention of Doom possessing this mind-transfer power was more or less a throwaway line explaining how it is Doom returns YET AGAIN from defeat. Still, that hasn't been retconned away, so Doom should still have this superpower.
THOR. Thor was, on a number of early occasions, able to create a "spell of forgetfulness" on mortals. Listings of the many things that Thor's Hammer has done is worth a post in and of itself!
AQUAMAN. There are significant menti0ons of the fact that Aquaman has a dolphinlike Sonar Sense in some of his Sattellite Era Justice League appearances. Also, Aquaman's Silver Age weakness (he could only survive an hour out of water) was overcome by a variant of his costume, which allows him to survive out of water for hours at a time.
IRON MAN. Besides Superman, nobody had more "one-use" powers than Iron Man's extendable armor. My favorite was his battle with the Hulk and Namor, where he donned a pair of HAMMERS over his HANDS. Or, there was his finger, through which he could shoot freon gas. Then there was the emergency remote control unit that let Iron Man pilot the suit from a distance. Jeez, I'm sure lots of people can make lists ten times this size, to be sure.