If you wait long enough, things come back around. Have a rack of fat ties, skinny ties? Paisley shirts? Bell-bottom jeans? It's just a matter of time before they are back in the avant garde.
Now it's "short" shorts for men. [Link is to a yahoo "shine" page, with pics of male models in standard length shorts (and one in what used to be called "hot-pants", and two in... what are those, buckle-free knickerbockers?) Beware: what is seen cannot be unseen! You have been warned!]
I have gone through about fifteen years of summers of shortening new walking shorts so that the hem would not hit the back of my calf. Somewhere between mid-thigh and a few inches above the knee seems normal. Otherwise, why wear shorts?
For running, of course, my favorites are as short and split-side as I can get away with...