Sometimes sites are down. That's life. But sometimes they are down because the site itself is down. Other times they are down because something in your traffic route won't let you get to the target site. If you've ever wondered which was the case, there's a nice site that helps in this regard. You can enter any site name, and they'll try a variety of routes to see if the site itself is down, or if there are just traffic routing issues that are keeping you from the site.