Is it possible to obtain chat room or bulleting board discussion about
a particular stock, e.g. from Raging Bull, Yahoo! or other sites, that
occurred in 2000?  How, other than asking those sites themselves?

Dear 010, 

This depends on the medium, and on the level of archive. 

Many chats are not archived at all. 

Many bulletin boards are. 

It is, at the end of the day, subjected to the webmaster of a
particular site: not all sites have the same archive policy. So, in
other words, this depends on the site itself. In some cases, it is
possible to find a page even if it is not archived by the site, on
which it used to be, if it has been saved by someone else.