Here is a very well written article about turtle penises (err.. sorry I mean phalluses) An excerpt:
"Without information to the contrary, I cannot help but imagine that some turtles might be in the habit of intimidating enemies with their erect 20-cm long, black, spike-tipped phalluses."
Yes there are pictures.
If that isn't to your taste perhaps you'll enjoy
this article on the mathematics of toilet paper. It has a picture of Sheryl Crow.