Heh, yeah, alt-search-groups and similar is where it started publically, though I think Rumbas is referring to the old MarketPositionTalk forums, run by the folks behind the oldest big SEO software (huge in its day).
Then there was SEF, WMW, the original Cre8pc newsletter and later the Cre8asite Forums, etc, etc.
There were days of search engines that indexed and ranked in real time - submit a page, see where it ranked, tweak it, resubmit, watch it go up or down, in real time. Those were easy days. Then Altavista, Excite, Yahoo as a directory, and Looksmart actually mattering (a little bit). Later Google getting its break providing SERPs for Yahoo, etc.
There were days when SEO wasn't. When search engines provided less traffic in a month than Google alone can provide in an hour now. When we still looked at banner exchanges, web rings, and links pages as sources of genuine traffic. When a mention in the right newsletter was worth more than being #1 for a SERP for a couple of months.
Workwise itself, there were the days when respectable companies thought SEO was basically hacking, and you had to sign an NDA just to talk about talking about maybe giving a proposal.
Days when the only companies hiring SEOs were either adult industry or the mom-and-pop businesses with nothing to lose. SEO was not just a dirty word, it was a word so outright filthy hardly anyone admitted to knowing what it meant.
It ought to make me feel old, but thankfully, I know at least half of you remember it too. (Probably 3/4 if alzheimers hadn't started to get some of us). Of course, its only old history in Internet years. Half of that stuff is still out there (or still being sold as SEO if you outsource to some places).
Some might look at all the waters passed under the bridge and wonder at how far the SEs had evolved and forced us to follow.
But most of us here know the truth. It was us that evolved, continually producing the next generation of spam and tactics that the SEs desperately strove to keep abreast of. Only a few search engines made it. Strange as it may seem, and argue as I'm sure most search engineers would, it is marketers and spammers that forced the evolution of search, and a heck of a lot of the entire success of ecommerce.