How do you find interdisciplinary collaborators for your research? I would like to know if someone knows whether there are IT solutions (websites etc) that help with meeting interdisciplinary researchers from local academic institutions (socal).
If you really want them local, the best social network is actually being social.

You can either attend conferences and university events in your city, attend seminars at other departments (some are announced in their webpages), or just send a series of polite emails to researchers working in thins you want. Just list the departments that may be doing something you like, browse their personnel, and skim their last publications to see if your research interests may be aligned.