Joined: Sep. 2004
I actually have some saved threads from ARN from 2000 and later. I just browsed through a few of them for nostalgia's sake: Mike Gene, Nelson Alonso, Richard Wein, and jazzraptor are some of the names I ran into. Also Phinehas and vividblue, who both still post at UD.
ARN was my first foray into debating with creationists, as 2000 was when the first Kansas science standards episode started, and Kansas Citizens for Science was formed to combat the creationists on the state school board. I'm sure that in many ways the general gist of the discussions hasn't changed, although I think the core UD crowd is really worse in some ways than anyone back then.
Then there was Dembski's ISCID, which had some pretty interesting stuff, and I ran a forum at KCFS for a long time before I closed it down due to, in part, being tired of some local crazy trolls. Also, at some point, the Panda's Thumb started (which grew out of a private list serve of science activists): it acquired some credentials and has served some useful purposes over the years, including the post mentioned in this thread.
Jason Rosenhouse's recent post (see the main UD thread) about UD is relevant to this little history of forums: UD was quite a bit more interesting when it started, but under Barry it has deteriorated.