Fingernails, erasers (on the back of pencils, man, dey yummy), nailpolish (stopped wearing it to stop eating it; gives cancer, it does), wooden chopsticks, toothpicks, straws, styrofoam cups, pencils, my lower lip.

For some strange reason, chewing on pens has never appealed to a chronic chewer such as myself.

EDIT: Oh yeah man and GUM like a mad-woman