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.
Venmon - Compact size system resources monitoring utility and multi-ping tool for Windows
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
TinyResMeter - TinyResMeter is a small tool that displays useful information about system resources in real time...
Better Uptime - We call you when your website goes down
Mousotron - Mousotron is a mouse and keyboard activity monitor and keeps statistics of your mileage. It's like an odometer or tripometer for your mouse cursor.