I was also having this "error opening socket" message today. (Before, everything worked fine!) Actually I donīt even get a html-page with the error; I rather have to read the error message it from the URL. Entering the IP-address of my website (as advised above) did not help either.
Oh, by the way: Donīt know if this is only a coincidence or if this might have to do with the problem: Today all of a sudden I also had some memory_limit problems with my frontend (php, Joomla). Never happened before ...
Any ideas? Thank you very much in advance!