Intelligent Design is a crock. It's a way to sneak Creationism into public schools and public discourse.
Proponents of Intelligent Design (or "I.D." as it is often known) use "sciency" sounding terminology and sleight-of-hand obfuscation to confuse people who are not up to speed on evolution. And they have been pretty successful---not because they have proved their position (they can't), but because they've tricked enough people into wanting to "play fair."
IDers want Intelligent Design presented alongside evolution as an alternate version of how life developed. As if one could simply pick the truth one prefers. But ID fails on the most basic level: it does not follow the Scientific Method (observe, hypothesize, predict, test, conclude). Any position that doesn't follow the scientific method is de facto not science.
Evolution is based on 150 years of evidence, observation, and testing. Its predictions and conclusions have been shown to be true over and over again.
ID is based on fantasy and fast talk.
The two are not equivalent. And putting them side by side is an insult to your intelligence. And that IS by design.
Male anatomy is a perfect example of evolution. No rational engineer (or Creator) would design an organism with its delicate reproductive organs in a vulnerable spot. And yet, for some reason, men's balls (testes) are fairly exposed.
That reason is because evolution can only build on what came before. Human beings evolved not through some divine plan, but through minute changes over millions of generations.
When our early ancestors were cold-blooded reptilians, it made sense to have testes on the inside of the body, because sperm develops best at about 93° Fahrenheit. But as our lineage became more warm-blooded (98.6° F), the testes moved outside the body to stay cooler. Thus, evolution improvised, using the infrastructure that was available at the time. It was a trade off: balls were more exposed, but the scrotum provided better temperature regulation.
It's a bad design, because it wasn't designed.