Is it Down? - Is it down can check if a website is down or is it just your PC that can not access it.
StatusNotify - StatusNotify monitors the status of 250+ cloud services.
Is It Down Right Now? - Network & Admin
IsDown App - Monitor all your cloud services status pages in one place
DownDetector - A simple service to tell you whether a website is down.
IsItDown RightNow - "Is It Down Right Now" monitors the status of your favorite web sites and checks whether they are down or not.