Check out this well-edited business casual look by DocHolliday on Styleforum. He wears a bold windowpane sports jacket but "mutes" the boldness with a small-patterned tie and solid white shirt. Definitely one of the best "what are you wearing" photos I've seen recently on Styleforum or anywhere else.
Are you curious about double-breasted suits but have held back from some reason? Perhaps you have unpleasant memories of loosely fitting double-breasted suits from the 1980s with extended shoulders. This Styleforum thread offers a nice corrective to those dated examples.
Additional links - Google images of the Duke of Windsor in Life magazine from the 1940s and 1950s wearing double-breasted suits