Automatic check if a Web site is up or down and response times for the server. Also provides some site statistics.

Monitor web sites, multi-page web transactions, and audio/video content. Some free services available.

Tool that checks the status of your website hourly. Free limited option available.

Customized monitoring solutions to ensure your site is up and functioning properly 24 hours a day, seven days a week.

Offers server monitoring with SMS notification. Covers web, mail, and DNS protocols.

Remotely monitors your server and alerts you instantly via SMS, MSN Messenger and/or e-mail. Each week you receive a server ranking and reports of statistics.

The 24-hour monitoring service that lets you know the moment your website goes offline.

External website performance monitoring and competitor benchmarking from test locations in Australia, Asia and US. Escalating alerts with a wide variety of alert methods.

Sends email or instant message notification of website service outages.