This userscript saves every visited page to the Internet Archive Wayback Machine (archive.org), if the page has not already been saved there within the last 30 days. This prevents duplicate saves (We don't want to spam the Internet Archive). Some sites are excluded by default (No need to archive google searches, for example). You can add more @exclude flags on your own.
It still works. Sometimes IA is simply overloaded or in maintenance mode.
Doesn't seem to work anymore. Throws an error when sending the archive request