A Web Secretary
Because I'm very lazy guy, automation always appeals to me. Many times it's the little tools that make all the difference. Chew Wei Yih created websec to automate checking web pages for changes in content. It scans an URI list, downloads the pages, diffs the changes and sends you email, if the page changed since the last run of websec. I run it from crontab once a day to check for changes on my watch list of web sites.
I couldn't find version 1.4 online, when I recommended it recently, so I put it up for download here.