This is an interesting design article on the theory "There is only one Cloud Icon in the Entire Universe" by Scott Hanselman. Hanselman dissects the idea of the cloud icon and who was the original.
This brings up the great point designers face that "everything has been done before." It was something I toiled with while in school. I felt having that idea was a cop out for people actually trying to use their brains. It was an excuse for everybody to just steal and copy from previous artist and I thought it was wrong. I never tried to steal my ideas but lets face it, I'm sure something I have done, even after my research, someone in this world has done something similar. But is something similar the same as copying? I am curious to hear your opinion on the subject.
Read Scott Hanselman's article here