BKB Limited Event Management 
Local and international races from a family fun run to marathons with online registration and past results.
http://www.bkbltd.com/W2 Promotions Professional Road Race Management
Aids non-profit organizations raise awareness and funds by organizing 5K and 10K runs and walks, marathons, triathlons, and family fun runs.
http://www.w2promotions.com/
Island Runner
Provides an international listing of runs that take place on islands. Races are organized by country. Also provides a message board.
http://www.islandrunner.org
Sports Fitness
Provides an event listing for duathalon, triathlon, and running events. Also includes an online registration service.
http://www.sports-fitness.com/events
Nude Runners Calendar
Provides a world-wide listing of nude running events. Also contains some links to the event sites.
http://nuderuns.com/
