I found a useful website application today that is great for the on-going maintenance of a website, and that will ask the question, IsMySiteUp?
The site is designed to monitor your website, and if a failure is detected, will notify you immediately via SMS of email. The site is also designed to provide you with reports that can be sent daily, weekly or monthly and supports a wide variety of internet protocols in use by most websites. The site will also provide comprehensive report statistics on the websites operating time. The site is clean and simple to use, and can be set up in no time.
A very handy tool for those that rely on internet customers, and cannot afford to lose them through downtime.