[chrishajer]

If your WP installation is at http://www.domain.com/wp/ then if you install the forum at http://www.domain.com/forum/ they are parallel. The bbPress installation would not be in a subfolder of WordPress.

Does WordPress come up at http://www.domain.com or http://www.domain.com/wp/ ?

There is probably a way to do it with mod_rewrite on apache, but I’m not sure I understand the question.