40 Free Web Services & Tools To Monitor Website Downtime | SmashingApps.com
StatusCake | Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Change detection and notification - Wikipedia, the free encyclopedia
Versionista: track changes to any Web site
Using ImportXML and XPath in Google Docs to Build a Web Page Monitor
How to Monitor your Website’s Uptime with Google Docs
30+ Free Web Services & Tools To Monitor Website Downtime
10 Free Services to Monitor Your Site's Uptime
diphur.com | home
SiteProbe - Website Uptime Monitor, Hourly Status Check
Internet Owl - Watching the Internet
10 Free Services to Monitor Your Site's Uptime
Follow That Page - web monitor: we send you an email when your favorite page has changed.
ChangeDetection - Know when any web page changes
CheckSite.us - Does this site work?
changeAlarm - Web Site Change Detection
SiteUptime - Website Monitoring Service
Site24x7 - Website Monitoring Service