Yes the longevity bar is part of our private activity hack.

A while back, Chruser set up an @zelaron.com e-mail service; if you PM him, he might have the link, so you can use that to register for vB.com and vB.org.

It could actually be done without a hack, I believe. You would have to run the query for the oldest join date:
SELECT joindate FROM user ORDER BY joindate LIMIT 1
in the PHP include, and then you might be able to do the math in a template conditional.