Another way that professionals in ergonomics and usability communicate with one another is through online forums. It is far easier and cheaper to organize than massive conferences, and provides a more interactive form of communication.
Forums work especially well to include professionals in countries that aren't well organized or represented in terms of societies and associations, or in countries that have very a smaller human factors workforce. Similarly, forums are a haven for usability specialists, as the internet is the predominant platform by which they make a living.
As a third and perhaps most significant benefit, forums can connect enthusiasts with professionals. When general users raise issues in online discussions, professionals can comment and clarify, thereby broadening public awareness and knowledge of their field.
The following are a list of a few active, popular ergonomics & usability forums
The Ergonomics Society Discussion Forums (United Kingdom)
About.com Ergonomics Forum
Ergoweb Discussion Forum
Create-a-Site-Forums
Opera Usability Forum
Webmaster World Accessibility & Usability Forum
*Several discussion lists can be found here