When it comes to website monitoring, Pingdom is the best web service available. Although Pingdom services are not free of cost, it is one of the most preferred service for website monitoring. Pingdom has now released a new desktop application for monitoring websites with Pingdom. You need to have an account with Pingdom to use this application.
Pingdom Desktop Notifier sits in your Windows system tray and uptime monitoring service does the actual monitoring, so you have the benefit of entire monitoring network. The Desktop Notifier checks in with the Pingdom service at regular intervals and alerts you with a popup if your website goes down.
The Pingdom Desktop Notifier works as a completely stand-alone application, but of course all the nifty features of the Pingdom uptime monitoring service are available at the click of a mouse button if you want to use them (it has a direct link to the Pingdom control panel).
The app works for Windows XP/Vista/7.
Download Pingdom Desktop Notifier