InfoMinder is a tool for tracking web pages. Very similar to KnowledgeBrowser. You can track a set of pages and receive an email notification (one email digest per day) with links to changed pages. The changed page links show the changes marked up visually. You can filter the pages using keywords. You can use this to track RecentEdits pages in wikis and changes to blogs.
It is available at http://www.infominder.com
-- DoraiThodla