More than 100,000 athletes annually attend what is said to be the country’s best runner's expo, held throughout the weekend before the Boston Marathon. The event showcases the latest goods, services and trends in the running and sports industry, including footwear, clothing and accessories, health food and beverages, seminars, clinics and demos. April 14-16. Open F 10 am-6 pm, Sa-Su 9 am-6 pm. Free.