IsZDown - Monitor the errors and status of the most popular websites and apps. Check whether they are down right now or not.
Is It Down Right Now? - Network & Admin
IsItDown RightNow - "Is It Down Right Now" monitors the status of your favorite web sites and checks whether they are down or not.
Site Down - Site down outage and downtime reports from SiteDown.co
Pingbreak - Pingbreak is an original and free monitoring service.
Is it Down? - Is it down can check if a website is down or is it just your PC that can not access it.