Lifehacker has made visible a valuable free resource for everyone – The U.S. Foreign Service Institute’s language classes material that are in the public domain. While it’s a bit dated, in terms of pedagogy and content, it’s still a good way to freshen up your foreign language skills or try to pick something up before heading out to the field. Course materials are in pdf, while audio material is in mp3. The Mandarin Chinese listening comprehension tests were amusing to listen to, but I wasn’t sure where the Twi tapes were headed, since I hadn’t read the accompanying text.
What else are you going to do on that long flight?