In general, it is a crime in California to record a communication (wherein there was a reasonable expectation of privacy) without the consent of all parties. See California Penal Code Sections 630 – 638 ( http://www.leginfo.ca.gov/cgi-bin/waisgate?WAISdocID=2039854621+2+0+0&WAISaction=retrieve).

Here is a link to state-by-state summaries regarding privacy-related laws (see http://www.rcfp.org/taping/states.html).