That sounds like a fun assignment; one to really make you think deeper than usual! ;)  I first thought of sign language, but that would be difficult to do if you didn't know it well. Then I thought of using clip art in the way that litteacher8 did-- in the form of an equation. Along those lines, you could organize your clip art pictures in a comic strip pattern where the reader would be obliged to follow each element of the argument frame by frame. Within the speech bubbles of a comic strip, you could use exclamation points and other punctuation to make your point. Also think about graphic organizers or flow charts to help you with this assignment; that way, the reader could follow the pattern of your logic which may help with the communication thereof. One advantage of pictures is that the human mind can look at them and immediately understand the communication more quickly than reading longer sentences. The disadvantage is in the lack of details that may make the major difference of communication worth-while.