Here are a few places you can submit your forum to.
http://www.forum-directories.com/forum_directories/forum_only_directories.html
http://www.forumregistry.com/registry/submit.php
http://www.gandalfdir.com/
http://www.ipbdirectory.com/
http://www.forumwebdirectory.com/
http://www.forumpromotion.co.uk/
http://www.worldforumdirectory.com/
http://www.perfectforumdirectory.com/
http://www.forumzilla.com/
http://www.forumshowcase.com/
http://www.forumfox.com/Add/Forum/
http://www.forumlibrary.com/
http://www.forumsinfo.com/
http://www.forumguide.info/
http://www.findyourforum.com/
