Seek office in the student government or other administrative bodies.
Get involved with popular organizations on campus and try to gain administrative authority.
Apply to be a columnist or regular contributor for your school's student newspaper or other popular campus publications.
Wear a silly hat. Top hats, propeller beanies and giant straw hats are sure to draw attention.
Carry a strange item with you at all times, such as a cactus or a stuffed iguana. If people ask you why you carry it, provide a bizarre explanation, but explain it as if it made perfect sense to you.
Stage a single-person mock protest for an obscure or insignificant cause, such as more beets in the cafeteria. This is particularly effective if your school is politically-minded.
Spend your free time between classes making scenes in areas where students gather. Hold up large signs with strange messages to draw people in, then put on an impromptu puppet show or interpretive dance.
Form a student group dedicated to yourself. Register the group with your school's administration and publicize the group through any appropriate means. If you're asked why you're important enough to have your own student group, reply with, "If you don't know, you'd better join and find out!"