Feedfry - The easiest way to create an RSS feed from a web page.
Update Scanner - Update Scanner is a Firefox extension to monitor web pages for updates.
WebRSS - RSS Widget - RSS to HTML - Display RSS for Free with Web RSS
WebSite-Watcher - WebSite-Watcher detects website updates and highlights all changes in the text. WebSite-Watcher monitors web pages, password protected pages, disucssion forums and much more.
Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
DELTAFEED - Get changes on any website as a News Feed in your Inbox