This is a great point and use case - I often worry about content I care about and have spent time thinking about disappearing. I run my own archive using <ahref="https://github.com/ArchiveBox/ArchiveBox">ArchiveBox</a>. I see that the Hypothes.is bookmarklet seems to work for archive.org but only in chrome. Also, it doesn't play nice with archivebox yet. I might have to see if I can get it working at some point.