Buddyup - Find another person with the appropriate skill doing your sport in your area. Over 20 sports including running, biking, skating, golf, tennis, and skiing. - http://www.buddyup.com/
Women's Exercise Network - Locating partners for a variety of sports, primarily for women. United States. - http://www.womensexercisenetwork.com/
PlayerLists.com - Free service allowing any amateur player of any age to find a team in many sports. Visitors can post "Player Resumes" or "Team Ads" and be notified when a match is found. - http://www.playerlists.com/
Match Maker - Find a player, team or partner to play with by registering. - http://www.sportisgood.com/sp/Match
AlwaysSports.com - Find a partner, submit sport photos, post on sport message boards. - http://www.alwayssports.com/