There was a forum catastrophe where everyone's profile was basically wiped and everyone had to rejoin in June 2003. Gaile is an admin so I'm guessing she can change her "join date".
Personally I joined during the D2 Classic Beta. That was, what?, 1999? It was at the beginning of the beta so whenever that was.
What this guy said. Except I joined in 2000. Can't believe I've been coming to this site for 9 years.. I was in middle school back then. Now I'm out of college and working. Sigh, time flies.