You can get expert opinion - ask your professor. If you are a graduate student or a new professor - ask your mentor. If you are an old seasoned professor - ask colleagues.
Informal networking is a powerful way to find ideas and bounce them off others.
There are several ways to do so in a more formal fashion.

• Use the Internet:
  There are newsgroups and mailing lists for people in the social science disciplines. There are ones for eating disorders, color vision, forensic psychology and many more topics. Books and Web sites can lead you to them. For example, check out http://www.healthfinder.gov/organizations/ for Internet resources.
  
  
• Conventions - specialized ones for each discipline.
  There is nothing like a major convention to get your intellectual juices flowing. Seeing other students, hearing research presented, and meeting prominent members of the discipline can generate too many ideas, sometimes! Conventions are organized by learned professional societies. For a good reference to those in Psychology - check out http://psych.hanover.edu/Krantz/psy.html Psychological Societies.