A tape by Marc Okrand and Michael Dorn. It offers instruction to non-Klingons on how to assert oneself linguistically within Klingon culture.
The best part is when they tell you how to order in a bar.
romuluS HIq vItlhutlh. "I will drink Romulan Ale."
HIvje' tIn yIteb. "Fill a large glass."
chuch yIqemQo'. "Do not bring ice!"