Ian: The big problem with folk activity websites isn't getting what's atarted going on, or is going on NOW, it's finding out when things STOP happening. Which is seriously often. Perhaps if someone suggests a site, insist that they give you an email address. Contact that address, say, once a month, and ask them if it's still going on ( obviously put this up front in the website entry details). And if there's no reply after a very short time - I'd suggest two goes- mark the venue as "perhaps dormant".

Just my $0.02