This is currently not available from the phone. The UCM system does provide Call Detail Records (CDR) for bulk access to all call activity: http://developer.cisco.com/web/sxml/docs
David,
I am sure the IP phone does not access the CDR (especially now with the need for SFTP) to get the call hostory. Most if not all IP phone commands are URLs back to the system. I am sure the IP Phone executes a URL to get the various histories. Do you know what that URL is dn what parameters are passed?