The Michigan Corpus of Academic Spoken English is a searchable collection of almost 2 million words of transcribed spoken English from the University of Michigan, including student study groups, office hours, dissertation defenses, and campus tours. Researchers use the Michigan corpus to investigate questions about usage, like "less or fewer?" (cf. this contentious Ask Meta thread) and more general topics, like "Vague Language in Academia." Browse or search MICASE yourself.
The Survey of American Jewish Language and Identity reports on the results of an online survey of 25,179 American Jews and 4,874 American Gentiles. Non-Jews say "klutz" but not "schmutz." The more Orthodox you are, the more likely you are to say "Good Shabbos" instead of "Shabbat Shalom." And so much more you'll plotz.
Amabil amico, Con grand satisfaction mi ha lect tei letter de le mundolingue. Arika Okrent, author of the new book In The Land of Invented Languages, lists 500 constructed languages, from the well-known (Esperanto, Volapuk, Loglan) to the utterly obscure (Neulatein, Rosentalographia, Mundolingue.) MetaFilter's own languagehat reviews the book. Okrent writes about Klingonophones in Slate. Alternatively, you might choose to learn not to speak Esperanto. Previously on MetaFilter, all you wanted to know about Loglan/Lojban but were too syntactically ambiguous to ask.
Essentalist explanations. Maintained by John Cowan, this list boils down dozens of languages, real, invented, and imaginary, to their pithy essences. "Japanese is essentially 16th-century Chinese, 17th-century Portuguese, 18th-century Dutch, 19th-century French and 20th-century English with an abhorrence of consonant clusters." "Esperanto is essentially Spanish with extra 'x's and 'k's." "Klingon is essentially Arabic spoken through a set of bulky false teeth." "English is essentially a half dozen other languages locked in a small room. They fight."