Shaun Anderson created a tool to keep track of changes made to 50 of the top Google webmaster guidelines.
The tool shows you how recently a specific Google webmaster guidelines document was updated. SEOs and webmasters must stay on top of these changes and this tool helps them do just that.
The tool is run automatically, where it will highlight any documents with changes in the past month or so in green. It does not highlight the specific changes but it does highlight which documents were updated and when.
Shaun said he built it using Google Docs and a simple import xml function. He hopes to add email notifications or other forms of notifications, so that webmasters and SEOs can be alerted of these changes.
I personally use page2rss.com to track changes made to pages but the tool doesn’t work all the clearly for Google Webmaster Guidelines changes.