Links
Tang Soo Do
International Assoc. of Korean Martial Arts (Dearborn Heights, MI): http://www.iakma.com/Home.htm
McHenry's Tang Soo Do (Includes links to Korean forms): http://mchenry.homeip.net/TangSooDo/
Tang Soo Do World (Good Tang Soo Do reference site): http://www.tangsoodoworld.com/index.htm
Tae Kwon Do
Kukkiwon (Seoul, Korea): http://www.kukkiwon.or.kr/english/index.jsp
AAU Taekwondo Program (USA): http://www.aautaekwondo.org/
Augusta Taekwondo Center (Augusta, Maine): http://augustatkd.com/
Hapkido
US Korean Martial Arts Federation (Jackson, MS): http://www.hapkido.com/
Friends
Progressive Tactics (Dearborn Heights, MI): http://www.progressivetactics.com/
Pierre Tae Kwon Do Club (Pierre, SD): http://www.pierretkd.com/
Mid-Maine Karate Kickboxing and Aikido (Pittsfield, ME): http://midmainekaratekickboxing.com/default.aspx
I will add other sites when I'm asked and know the people asking.