From what I remember, I first joined the RW Forum in late 2002, so it's been going on quite a while here at least. The only real major tournament back then was the Never Seen Before Fic League and I distinctly remember the fourth series either being underway or finished by the time I joined.

Dear God, I'm old.

EDIT: Ah, perhaps this might help :
Ye Olde History of Fanfic? Thread