Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
PingDoctor - PingDoctor is software that is considered to be the most powerful and easiest to use network route analyzer.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
NetCrunch Tools - Our free network tools offer ping scanning, SNMP scanning, port and network service scanning, and more.
Better Uptime - We call you when your website goes down