If you're maintaining a website or FTP server, then you need some way of warning you in the event of a major system failure or connection problem.
Simon is a useful monitoring tool which checks servers for changes or failures and notifies you via e-mail, sound, speech, or other means. You can use it to track updated sites and to alert you when an important server goes down or recovers. This also makes it suitable for those that just want to check when their favorite sites are updated too although it's a rather long winded way of doing it when you've got RSS feeds for that job. However, if you really like a site and for some reason it has no RSS feed, Simon could be used to monitor it.
All tracking is done via Simon's Monitor window. It does look rather intimidating at first although many of the features you won't need if you're just tracking changes to a few sites. The Monitor window enables you to see at a glance the current status of all of your monitored websites, servers, and applications. You'll see data relating to a site's up-time percentage, how long ago since the last failure occurred, and when the next check will occur. There are also a ton of other stats that you really don't need unless you're a network administrator that needs complete control over monitoring.
Simon is really aimed at those that need to have full control over the monitoring of websites and FTP servers but if you really have no other way of checking for updates, then it's a very thorough tool.