Netformx - Netformx helps Cisco partners & Solution Providers deliver multi-vendor IT solutions quickly & effectively while improving profitability & customer success.
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.
Super Monitoring - Affordable uptime monitoring service for webmasters and website owners. Have your website or server checked every minute and get alerted instantly.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Better Uptime - We call you when your website goes down
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting