Jonathan Rentzsch wrote a little JavaScript utility to help recover from 404:Page Not Found errors. It takes the current URL in your browser, and uses it to retrieve the archived version of that page from Google’s cache. Here’s Rentzsch’s discussion on Google cache hacking. Another blogger, Fuse, developed an improved version. Just drag the preceding link to the “Links” toolbar to add the bookmarklet to your browser. Next time you hit a 404 error, or want to see what an older version of a page looked like, just select this link to get the cached version.
Jon Udell’s blog pointed me to this tool. Jon mentions that the Internet Archive’s Wayback Machine is another useful depository of old Web pages. Can it be addressed by JavaScript bookmarklets in the same way as Google’s cache?