Even more important than articulating French fluently is understanding those that do exactly that—I try to improve my listening comprehension by watching films in French (dubs of films I know anyway, possibly with subtitles) and, sometimes, listening to French satellite or internet radio. I also listen to a fair share of French music, but I doubt that helps a lot. Going to France and speaking with locals is, of course, the non plus ultra of learning to understand, well, locals…