Mon.itor.us API

Mon.itor.us
From their site: Free network and site monitoring. mon.itor.us provides 24 x 7 network and website monitoring serviceim with personalized interactive interface, where you can add server performance and availability tests, get uptime reports, add contacts to get the alert notifications. Tests will be performed from geographically distributed servers. The monitoring will be performed outside of your network firewall and on the application level.