apparently, the kanji "hito" is written three times on the palm of the hand with a finger (a common way to explain stroke order in japan). it is then symbolically swallowed before going out on stage. the people i spoke to said it wasn't about becoming the character (noble idea, jackie!) but about negating the effect of the audience. once you swallow them they can't make you nervous!
there is an expresson "hito wo nomu" which literally means "drink people". i'll have to find out exactly what this one means. in the depths of superstition here.
by the way when i sang in the opera it was bad luck to whistle in the dressing rooms. some of the old timers would get really angry if you forgot and let loose with a catchy tune from the show.