Find your oldest Usenet post, post a link. (And link back to here and tag four others, if you wish)
The earliest post from me was May 25 1991, although I found a reference to me from July 1990 here (I had e-mailed something to the poster, as I didn't have Usenet posting privileges in those days as a mere undergrad).
I did just find a cool coincidence : a reply by one "Charles Stross" to a post of mine from rec.arts.sf-lovers here.
I wonder if it was ... you know ... that Charles Stross. He did sign as "Charlie" ...