Watcher1 is a simple utility that can monitor a webpage, either by its URL or be sending pings and then alerting you to changes or problems via e-mail. Therefore, if your page ever goes offline, you'll know immediately what's happened.
You can set the time interval between each check and configure two different e-mail addresses to send warning messages to. The e-mail contains a link that takes you to the programs log where you can view in more detail what happened and then either save or delete the message.
Watcher1 supports the HTTP protocol and you can configure it to check for the webpage size (ie: 12000 bytes, etc.), or have it look for specific text in the page (ie: if you're checking cgi, asp, or exe output from a web script, etc.). The program is very quickly to setup and run and there's no installing to do - you can run it directly from the EXE file.
A very useful program that will give you added piece of mind about your website.