[thelist] best way to create a forum

[John McRaven]

Hey,
  I have created forums a few different ways.  I can make each message a
different file, and use files to do it, put messages in a database, etc.  My
question though, for a big site, where there could be a lot of messages on
the forum, what is the most server efficient way to make a forum (definitly
not limited to the ways mentioned above)?  Thanks for the help.

John