Some Kryptonians, before they develop the ability to fly, can jump and leap incredible heights and distances due to their incredible muscular structure in addition to their low weight. This Leaping can be considered a precursor to flight, but is not entirely due to the Photonucleic effect.
Known Characters that have demonstrated this ability
Clark Kent has demonstrated this ability in Smallville.
Superman can achieve giant leaps but he rarely uses this ability instead he uses his flight ability.
Davis Bloome has demonstrated this ability in Smallville.
Jor-El has demonstrated this ability in Superman the animated series.