CarpetDog

mon.itor.us provides free real-time personalized Ajax dashboard interface, checks server performance and availability, generates uptime and availability reports, tracks visitors, checks system resources, and alerts its users in case abnormalities are detected.
The service also provides tools for performance research and web analytics. Thus you can use the service to benchmark your site performance versus competitors effectiveness. So you can analyze web traffic tendencies and observe the performance all in the same place.