Below are links to organizations focused on different disciplines of design, usability, and user experience.
ACM – Advanced Computer Machinery
Focused on educational and scientific computing society for those who have computing as a science as profession. The ACM publishes regular issues of “Interactions” an online magazine for anyone interested in human-computer-interaction.
information Architecture Institute
Human Factors and Ergonomics Society (HFES)
Human Computer Interaction
Interaction Design Association (IxDA)