I disagree with Suresh. I think we should always be a bit selfish and think what is best for our site, our users, and people who find our site by googling.
I think it would be better for us if someone (OP or anyone else) posted an answer here, and then the OP accepted the answer. The answer could be, e.g., a link to MO and a short summary of the answer there, or a full copy-paste if it makes sense. The question should be left open.
This way our users will get some useful information, too. People who don't actively follow the question but every now and then check the front page will notice that this question has now some answers. People who use search engines will get useful information through our site more quickly; accepted answers are easy to find while comments are easy to miss. Our users can write additional answers and provide more information. And in general, an on-topic question with an accepted answer looks much more attractive than a question that was closed (also in our statistics...).