It depends entirely who 'others' is, their attitude towards/knowledge of SO, and the context in which this conversation is happening. It's one thing to be asked in an interview "Tell us your top-ten resources for getting your work done and why?" It's entirely another thing to be asked "Why are you constantly surfing to all these third-party sites, some of which (e.g. Careers.SO) appear to be jobsites? Aren't you working?"
If 'others' means managers, then never tell a non-technical manager (or higher-up) "I spend some time at work asking or answering code-related questions on another website".
Also, legal types will often wet their pants at the prospect of disclosure or code/ license/ IP tainting. The less open-source-friendly the company, the higher the danger.
As to developers, some sneer at SO (in some cases, with good reason). Most developers have a backchannel of personal contacts, mailing-lists, forums, user groups, chat channels, even Twitter followers, where they can more quickly source very high-quality opinions or recommendations, without the drama and narrow scope restrictions of SO. Ever tried to ask for a package recommendation on SO? Tough. A purchase recommendation? Tough. A semi-objective question which nevertheless calls for years of experience from your audience? Tough. All will be gleefully closed with the snarktastic putdowns which have made SO, ahem, notorious - in some language communities worse than others. There are, of course, also developers who find SO useful. So, know your audience before you tell them.
As to non-technical types, I can't see how SO would ever even come up in conversation, other than "I/My kid wants to learn to code/ script MineCraft/ program a home controller/ program Hangman etc. How do you do that?"