I was listening to the news this morning on the radio when I heard this simile about the oil spill: "The oil looks like melted chocolate on the surface of the ocean."
I think I would use a different comparison. When I hear it looks like melted chocolate, my first thought is, "Yum" and then, "That doesn't sound so bad." Really, imagining ducks and ocean wildlife covered in melted chocolate doesn't have as negative a visual impact as some other things.
Now, if they compared the oil spill to baby diarrhea or rotten guacamole then I would be totally turned off. I guess it just depends on what the news slant is that day.