planning on being one ;)
It all depends on what area of graphic design you go into and what company you work for. It could be designing ads, commercials, publications, books, magazines, video games, and so on and so on. My mother is a graphic designer for LSU and she does their newsletters, publications, magazines, billboards, and things like that.
Well my job title technically includes graphic designer (although it needs the sub-text "No Artistic Talent") - and I work for a print shop / signs shop. So I setup signs, brochures, postcards, business cards, posters, banners. All that sort of stuff.