Jim recently pointed me to the English Language and Usage Stack Exchange site. For those unfamiliar with Stack Exchange, it's a collection of websites on various topics that are designed for asking and answering questions.
Stack Exchange can take some getting used to. It's not a general discussion forum; the specific goal is for people to ask “practical, answerable questions based on actual problems that you face” and receive answers to those questions. In the case of the ELU site, though, there's a bit of a fine line between the sorts of questions that are okay to ask (about, for example, word choice, usage, grammar, etymology, and dialect differences) and the sorts that aren't (such as simple basic questions about definitions, pronunciations, and synonyms that can be easily answered by a dictionary, a thesaurus, or a web search). For more info, see the FAQ.
In practice, in my brief time on the site so far, there appear to be a great many questions by non-native English speakers of the form “Is this phrase grammatical?” My vague understanding is that such questions are fine and within the intended scope of the site, though I'm still a little unclear on what the boundaries are. Anyway, there are also a bunch of other kinds of questions.
I'm still getting used to the site, and I'm not sure whether I'll spend much time there. But so far I'm intrigued.