Patent Café’s List of Inventor Organizations by State
http://12www.patentcafe.com/inventor_orgs/clubs.html
If you don’t find an inventors group listed in your area on this website the following sites are also worth a look:

Inventor’s Digest Online Organizations for Inventors
http://www.inventorsdigest.com/connect/orgs.html

Ibiblio List of Inventor’s Organizations
http://www.ibiblio.org/patents/txt/invent.txt