Versionista

Versionista crawls, archives, and monitors Web sites for changes. Versionista delivers email reports and instant alerts detailing exactly what text or HTML has been added or removed on every monitored page. Program Versionista to crawl and monitor all newly found pages, or just those that meet your criteria. Further customize Versionista to filter out specific areas of a page (such as footers, sidebars, or other areas with frequently changing but irrelevant content) to only focus on content that interests you.