I'm a fluent speaker of just two languages, English and Lojban. (You may hear me mention Lojban again when someone asks a question of the form "is there any language that does X"-- Lojban does a lot of weird things!) I can read Esperanto, but I don't speak it well. I'm picking up Toki Pona. I'm planning to seriously study Spanish and Potawatomi. Some languages I've been interested in, to varying degrees: Sanskrit, Maori, Mandarin, Russian, German, French, Italian, and all of the conlangs but particularly: Laadan, Teonaht, Klingon, Solresol, and for a cherry on top I'll say the Lingua Ignota. Word to Hildegard.
What interests me most about language though isn't any particular established idiom, but the social process itself of conscious and unconscious negotiation of the meaning and use of symbols. I've found that process easiest to watch in small, new languages, where the ground is unsettled; there every attempt at communication must be very creative, and particular acts of communication can dramatically and visibly change usage. Besides studying the youngest living conlangs, such as Lojban, Laadan, Klingon, and Toki Pona, I have also joined with small groups of people to create tiny new experimental languages. My first collective language project ("J. B. Blingo") was with a group of school friends, and since then I've started and participated in various projects online.
My latest project, called qww'xzx, is pure experimentation and art, open to all. I started it with my own pet project idea of a ladder of languages, each slightly more complicated than the last, as a gradual way of constructing and then teaching a language in bite-sized stages. There's a seed group for the whole language, and also now a seed group for the first level/slice, qww'xzx-l. Anyone's welcome who'd like to learn or help us invent.
Thanks for existing, Linguaphiles! You hear LiveJournal mentioned sometimes as an old thing that existed before MySpace and FaceBook were so obviously cooler, but you and I we know the truth: That LiveJournal is that much more beautiful a place, now that those who are attracted by shiny things have blown away, and those of us who value more words and human connection are who remain. Cheers!