Mon.itor.us provides a fresh, novel approach to IT and Website monitoring. Need to reduce site downtime? Provide superior user experience? Measure the traffic? Find reliable hosting? Compare your site performance with competitors? Understand who are your visitors? Achieve continuous business operations? Quickly diagnose and prevent issues? Promote your website? Mon.itor.us addresses these needs for individuals and organizations of all sizes. And it is easy and free anyone can use it in 5 minutes .
You can also try http://www.monitis.com which is premium version of mon.itor.us with more advanced features, frequent check intervals and other cool stuff