For a casual gig (most all my gigs are casual) I wear either a plaid or Hawaiian shirt with Docker pants. For a more formal gig, I'd wear either a plaid or Hawaiian shirt with Docker pants. I'm only comfortable when I'm casual.
Remember the 2 million $ birthday bash Tyco CEO Dennis Kozlowski gave for his wife ~ a year ago? Entertainment was by Jimmy Buffett, who wore... you guessed it, same thing he always wears. Gotta love it.