forumize 

The act of foruming, whether it be posting in a forum, reading through a forum, or anything else involving a forum.

Dude, let's go forumize on smogon.

forumize by Batpig July 21, 2005

forumite 

A regular at any given Internet message-board system, or "forum".

The forumites of the GameSpy Forums are often plagued by the whining of n00bs.

forumite by Macavity October 30, 2003