PingInfoView - PingInfoView is a small utility that allows you to easily ping multiple host names and IP addresses, and watch the result in one table.
Site Down - Site down outage and downtime reports from SiteDown.co
SmokePing - Smokeping is a tool for measuring latency.
Is it Down? - Is it down can check if a website is down or is it just your PC that can not access it.
PingPlotter - PingPlotter is a troubleshooting tool that helps IT professionals and neophytes identify, diagnose, and resolve network issues.
UPDOWNtoday - UPDOWNTODAY allows you to check whether the website is down or not.