People have been enjoying a wide variety of sports since at least the time of Ancient Greece. In the Athens 2004 Olympic Games alone, athletes competed in about 300 categories of 28 sports -- and the list seems to get longer every time.
In fact, that is hardly surprising, as a glance at my Webster's dictionary confirms. There, "sport" is defined as: "Any activity or experience that gives enjoyment or recreation; pastime; diversion."
So, reflecting the near-limitless scope of "sport," and humans' boundless imagination in pursuit of "recreation," another new -- though not yet Olympic -- sport has been invented and recently introduced in Japan. That sport is "extreme ironing."