The invention enables “low attention recording,” i.e., recording that need not appreciably affect interaction of a recorder (i.e., a person in control of a recording unit according to the invention) or others with the environment in which the recording is taking place. The low attention recording...http://www.google.com.hk/patents/US6934461?utm_source=gb-gplus-share專利 US6934461 - Low attention recording, with particular application to social recording
