In an interview, I'm looking for people who can take advantage of any available resources to achieve their goal more efficiently/effectively.
If you were to say to me "When I get an exception, I sometimes post it on stack overflow to see what the problem is", I'm going to take that as a negative without additional context. It implies you don't know how to debug code.
Conversely, if you were to say "I often use SO to cross-reference, or research potential alternatives", that's a positive - it shows you've understood the problem, and are evaluating multiple options for resolution.
The one thing I don't want is someone who's going to keep reinventing the wheel. If someone's solved this already (and the license is appropriate) use it! You just saved yourself days/weeks of time, and helped make sure the project is delivered on time and under budget.
Also.. If you mention SO... Are you proud of your question/answer history? If so, consider including a link to your profile on your CV.
As an employer, seeing how someone approaches problems (and takes feedback/criticism) can go a long way to giving a fuller picture of a candidate.
We have one employee who completely bombed in the interview. Really didn't demonstrate any of the skills we were looking for but his SO profile was thoughtful, detailed and showed a huge breadth of knowledge. So we gave him another shot (and some written work) and he aced it (and we're very happy with him).
I can't say we'd have taken him on the profile alone, but it was enough to make us stop and look twice.