National Radio Data - http://www.nationalradiodata.com/
Frequency scanner resource. Includes the United States amateur callsign search and also has a forum. Paid registration.
PopularWireless.com - http://www.popularwireless.com/
Discover wireless communication, the radio hobbies and more.
Radio Amateur Old Timers' Association (RAOTA) - http://www.raota.org/
Seeks to keep alive the pioneer spirit and traditions of the past in todays Amateur Radio by means of personal and radio contact, whilst being mindful of any special needs.
Radio Amateurs of Canada - http://www.rac.ca/
Provides liaison with government agencies and carries the amateur voice about regulatory and spectrum issues to the discussion table with government and industry leaders, nationally and internationally.
South Coast Amateur Radio Service - http://southcars.com
Aims to assist those seeking to contact other amateur radio stations, or areas, to provide weather and travel information, whenever needed, if available, and to assist in emergencies.
This Week in Amateur Radio - http://www.twiar.org/
Features the latest news and has many special features on various items involving technology and amateur (ham) radio.