I happened over to SO today and saw that there are still a fair few TeX questions being asked (and answered!) there. I left a few "try this on http://tex.stackexchange.com" comments, but I feel that those work best if they are added very soon after the question is asked (and before any answers are posted). So those who are a bit more regular visitors to SO might want to look out for such questions.
Also, if anyone has a good comment that we could adopt as a default for leaving on such questions, please let us know (and format it suitable for cut-and-pasting, so ensure that URLs are fully visible).
You can find an entire community on the [TeX StackExchange](http://tex.stackexchange.com/), where no TeX-related question is too small.
It does not say "You should ask this question elsewhere." It does not say "People who use TeX should use the TeX SE instead of SO". It just says that if you are looking for a focused TeX group it's there.
I browsed the tag-set. and posted a few comments. one question asked something that we had already answered quite fully here. In cases like this, I suggest that we give a reference to the question on TeX.SE, so that we also demonstrate that the answer already exists, and not only that TeX.SE is a good place to ask the question..
Simply redirecting people to this site saying "maybe you can find an answer here" is incredibly unconstructive and should imho be avoided. Such advertising (I'd call it advertising, yes) is not appreciated by those running the site nor those who are asking the question.
What I'd rather suggest is that links to this site should be included as a helpful addition to an already posted answer, around the lines of "should you need more help, you are welcome to use SE's LaTeX site as a compliment".