A very useful source of authentic listening material is radio news. Most countries have an English-language news service that can be recorded, otherwise the BBC World Service or Voice of America can be picked up with the right equipment. One way of exploiting this material is to right a summary of the news with eight factual errors. Students listen to the report and have to identify the errors. Of course, the errors can be grammatical as well, focusing on a structure that you have been working on in class, but the laws of nature dictate that the structure you are presenting doesn't come up in the broadcast, or that the examples directly contradict what you have taught your students about the structure in class. "C'est la langue."