Are there Latin language clubs were people will hang out and only speak latin to each other? Are there any isolated populations were they still speak latin? How much do we know about what conversational LAtin sounded like?
I know that some of the schools here in Sydney have clubs where the students act out Latin plays, learn about Roman culture and converse in Latin.
About ten years ago I stayed at a monastery in France during Holy Week. The monks spoke very little English and my French was pretty woeful. We managed to have basic, but quite comprehensible conversations, in Latin.
When these clubs converse in Latin do they just talk or do they use dictionaries? Are there people that have a speaking level of knowledge of latin or are they just able to provide information in “broken” Latin?
My Latin is far from fluent (even more so in recent years), but I don’t see why being fluent today would be impossible. It isn’t a skill that is usually emphasized in Latin education, but if you invest a sufficient amount of work it should be possible.
Of course you can’t really guarantee that your style is authentic (compared to what?), but being understood is definitely within range.
Actually learning to speak substantial Latin is one of my long-time “when I have time”-projects, but I’ll have to start Japanese this summer at my University, so this will be delayed once more.
There was a professor at the University of Minnesota about 15 years ago who specialised in spoken-word records of classical poets – he could also speak Latin ‘naturally’ – that is, not the sort of recitive sing-songy stuff you might hear at a Mass (whether an actual Latin Mass, or a ‘faux Mass’ in a movie).
He came and spoke to my Catullus ‘n’ Ovid class, and I recall one boy blurted out, ‘It sounds like a real language, like Italian, or something!’ 
The professor explained that he and other linguists have been able to reconstruct what daily spoken Latin sounded like using metre and stress from the poetry.
I’ll do some poking around and see if I can find his name, and some of his recorded work.
That said, it drives me bonkers when I see movies that take place in Rome, and the pronuciation of names and words is all over the place! Modern English speakers say Cicero and Caesar with a soft ‘C’ – fair enough, I suppose, but be consistent. Amongst the other interesting anachronisms in Caligula, for example, are the ecclesiatic pronunciation of names (Gemellus gets consistently a soft ‘G’, and someone else whose name escapes me has the ‘C’ in his name pronounced as a ‘Ch’. Crikey, don’t get me started about the bizarro history in that movie…we’d be here all day.)
I spent a year in a Latin-reading course as ‘suggested’ by my dissertation director (he also directed the course), and he insisted on ecclesiatic pronunciation, and used to ride me because I always used classical pronunciation, as I had been taught (classicists will tell you that church Latin will get you odd looks at conferences, as classical pronunciation is standard). I finally had to tell him that I was a Ciceronian, not a Christian; we had a rough working relationship, but that made him laugh, actually!
There are several organizations around the teaching and study of Latin in primary, secondary, and postsecondary schools in the United States. The National Junior Classical League is the high-school organization, which has chapters in hundreds of schools and in every state throughout the United States:
Its college counterpart is the National Senior Classical League:
Both organizations operate under the auspices of the American Classical League:
These organizations sponsor frequent conventions and contests, including an annual national convention in the late summer. The conventions almost always include several contests and other events where Latin is spoken, although the organizations conduct their business in English.