Diff-IE For IE9
I was recently told about a new add-on for Internet Explorer 9 (from @msftresearch) that highlights changes to the site from the last time you visited. It seems to work very well. If you visit a lot of sites daily, this add-on works wonders to save you time!
Diff-IE is a prototype Internet Explorer add-on that highlights the changes to a page since the last time you visited it and enables you to view and compare previously cached versions of the page.