Top Ten Endangered Languages, selected by a linguist. Yes, top ten lists for this sort of thing are silly, but there are some wonderful tidbits in here which it's going to be a damn shame for humanity to lose. For instance:

[Jeru] is generally believed that Andamanese languages might be the last surviving languages whose history goes back to pre-Neolithic times in Southeast Asia and possibly the first settlement of the region by modern humans moving out of Africa.

The closest relative of Nu is !Xóõ (also called Ta'a and spoken by about 4,000 people) which has the most sounds of any language on earth: 74 consonants, 31 vowels, and four tones (voice pitches).

Yuchi nouns have 10 genders, indicated by word endings: six for Yuchi people (depending on kinship relations to the person speaking), one for non-Yuchis and animals, and three for inanimate objects (horizontal, vertical, and round).

Guugu Yimidhirr (like some other Aboriginal languages) is remarkable for having a special way of speaking to certain family members (like a man's father-in-law or brother-in-law) in which everyday words are replaced by completely different special vocabulary.

Oro Win is one of only five languages known to make regular use of a sound that linguists call "a voiceless dental bilabially trilled affricate". In rather plainer language, this means it's produced with the tip of the tongue placed between the lips which are then vibrated (in a similar way to the brrr sound we make in English to signal that the weather is cold).

Of course, who are we to judge? Maybe there are reasons these folks prefer to speak to their children in relatively sane and reasonable Indo-European languages. Perhaps the Oro Win found that blowing raspberries was just not as desirable a means of communication as Portuguese.

Via Languagehat.