Show HN: Super Mail Forward, an HTML email that evolves as you forward it
This reminds me of the old concept of "tab damage"[1] on usenet/mailing lists. People used to leave little "devices" in their signatures that based on this that would point to the number of times a message had been forwarded or quoted, because client software would typically indent the quoted message.[1] http://linuxmafia.com/~rick/afw/#tabdamage