From Esquire Magazine (author not named) via MSN March 27, 2009:
Why It's OK to Wear a Rumpled Shirt
In praise of slightly wrinkled clothing, an emotional investment unto itself.

A wrinkle-free shirt is like a football uniform without grass stains: It makes you look third string. Hesitant. Pretty. It makes you look correct, yes, but life isn't correct; it's wrinkled. Anyway, wrinkles are a badge. They're evidence that we've hailed a cab or reached for our wallets or leaned back in our chairs or fought something. They're proof that we've moved.

A wrinkle-free shirt is for someone who wants to cover his tracks. It's a safe choice, and in style, safety is not a virtue. Texture is. We should look flawless only when we're standing in front of the mirror in the morning and congratulating ourselves on how wonderful we are.

Then, starting immediately, our clothes should start gathering a history. Attempting to convince everyone around us that we look this sparkly, this utterly without stain or spoil, is pretending we're someone we're not.
As a "slightly wrinkled" kind of gent myself, I appreciate that.