I have the forums as my home page so the outages manifest in one of three ways.
I log onto my browser and get a 'page not found' message (also typical with a line outage) but If I type something into a search bar the rest of the internet is there.
The forums are also on my 'favorites frame' if I open a new tab so I might click on the box there and get another 'not found' message but still have access to the rest of the internet.
Or I get a 'java.net' fault message like the other day which seems to indicate a Microsoft server problem as those sorts of messages don't appear on Unix servers.
Don't know if this has helped but I will keep my eyes peeled and paste you any further error screens or details that I notice.