The Boeing 787 has been doing some test flights off the coast of California and Mexico. Lately they have been heard on 8843 kHz working San Francisco ARINC. I have also logged them on the Boeing Test Flight frequency of 11306 kHz talking with Boeing Seattle. To find out when the Boeing 787 and other flights are up see FlightAware.com.
Below is audio recorded from 8843 kHz as they coordinate with San Francisco radio for various clearances.Listen to the audio