Anybody who's ever heard of Star Trek probably knows that the Klingons were one of the mythical alien races from the series. According to the Klingon Language Institute, Dr. Marc Okrand intended Klingon to be a fully functional language that had its own vocabulary, grammar, and usage.
If you wanted to insult someone gravely in Klingon, you could say Hab SoSlI' Quch which means "Your mother has a smooth forehead." Never considered the friendliest of fictional alien races, Klingons say nuqneH instead of "hello"; NuqneH translates roughly into "What do you want?"
Spoken Klingon sounds like a cross between a semitic language (like Hebrew or Arabic) and an eastern european language (maybe Russian or Polish). I'm very tempted to learn Klingon but its use would be marginal at best; I'd be better to learn Mandarin Chinese or German rather than an artificial tongue spoken by a couple of thousand sci-fi devotees.
Now, I must tugh (hurry up) and bring this post to a bertlham (an end). I shall chegh (return) when my laundry is done. Mevyap (Enough) of this Klingon!