The National Organization for Amputees is the Amputee Coalition.
Here are some other helpful websites created by various organizations designed to help amputees throughout the world:
http://www.disabledtravelers.com/disability-basics.htm - Disability Basics (Thanks, Michelle!)
http://www.lessthanfour.org/ - An Online Community for Amputees
http://www.hphdhelp.org/ - Website dedicated to Individuals living with Hemipelvectomy and Hip Disarticulation
http://achillestrackclub.org/ - An exercise club to improve your overall health and meet an outstanding group of people
http://www.opfund.org/ - A fund for amputees to enjoy personal achievement, physical fitness and social interaction
http://www.challengedathletes.org - Raises money to help people with disabilities lead an active life
http://www.limbsforlife.org/ - An Oklahoma City Foundation for Amputees
http://www.ncpad.org/ - The National Center on Physical Activity and Disability
http://www.usparalympics.org/ - U.S. Paralympics
http://www.nagagolf.org/ - National Amputee Golf Association
http://www.ampsoccer.org/ - American Amputee Soccer Association
http://www.activeamp.org/ - The Online Connection for Amputees with an Active Lifestyle
http://www.mtb-amputee.com/ - An amputee group committed to mountain biking
http://www.aopanet.org/ - American Orthotic and Prosthetic Association
http://www.oandp.com/ - The Global Resource for Orthotics and Prosthetics information
http://www.360oandp.com/ - An Orthotics and Prosthetics Online Community for information
http://www.stumps.org/ - An Amputee Support Group in California
http://www.timeanddate.com/holidays/un/international-day-persons-disabilities - Int'l Day for persons with disabilities
http://www.alwaystri.net/ - An inspirational young woman and elite athlete
http://www.cameronclapp.com/ - An inspirational young man and outstanding athlete
http://www.limbless-association.org/ - The leading UK Amputee Charity