After a little discussion in the comments section about the connection between biology and technology, I thought I'd like to see these three designs side by side.
I hesitated, as the two designs to the right are nice things, while the one on the far-left is not nice at all.
So, please take this in a friendly way: I don't mean the three are equivalent.
Right: Male reproductive system
To quote Margaret on the similarity among designs:
"It's more than coincidence, but it's not deliberate."