- ActaPhysica - Free social networking platform for the physics community, enables users to network with peers in the worldwide physics community and share knowledge, ideas, problems and resources.
- PhysOrg Discussion Forum - Applied physics, nanotechnology, quantum physics, and semiconductor technology. Also discussions of the latest physics news.
- Scott Watson's Physics FAQs - A list of FAQs (Frequently Asked Questions) regarding Cosmology, String theory, Relativity and General Physics
- Physics Forums - Bulletin boards on physics and related subjects. Includes related polls and a list of active threads.
- Advanced Physics Forums - Intended primarily for physics majors, graduate students, postdocs and faculty. Get meeting information, theoretical and research information and exchange of ideas. Meant for the physics community throughout the world.
- QuantumBrain - Collaboration between a neuroscientist based at the University of Oxford and a quantum physicist based at the University of Queensland. Includes blogs and philosophical musings.
- Groupsrv.com - Physics Forum - Discussion for scientists.
- LaserEnthusiast.com - A forum for people interested in lasers.