Superuseless Superpowers is a blog by an anonymous cartoonist who has taken up the task of chronicling the most useless superpowers. Above is his picture of the superpower 13th Bullet Proof -- being completely safe from 1 out of 13 bullets shot at you.
I gotta say that the most useless superpower I ever saw was in the old Palladium role-playing game Heroes Unlimited. It was clock manipulation: the ability to stop or change the time on a clock through psychic powers. I'll take invisibility or wingless flight over that any day.
Link via Radley Balko
For example: You can fly but you are insanely afraid of heights.
It's quite funny ! Like "Captain Acid" who previously sent acid fluids with his barehands and now only sends soft shampoo, or Mental who can make you do anything ... only if you're intend to do it !