Participating in the Creative Contests is one way to get a new rank. You have to be the winner in order to get those. Contributing to the site, either through creativity, analysis, or community leadership, can also give you a rank of Guru if the higher ups recognize your contributions. (All of this can be found in the link Angerona provided, btw.)
There is also the Springtime of Youth rank, though I'm not sure ZeaLitY gives that out anymore.