Due to a crazy increase of bot signups I have switched moderation of new memberships on. I've never done that before, but I think that means that only I (and no other staff) can manually approve memberships. Anyways I hope to upgrade us to the latest version of vBulletin (which will hopefully come with better security) eventually, but it won't be free so I can't do it right away. Anyways if your username and email don't scream "BOT" to me, you'll be approved, don't worry.
edit: Well I went ahead and closed memberships altogether and people who want to sign up must now email me personally. We haven't had a legitimate signup in ages anyways. Rest assured if you are 13 or over and wish to be a member of this forum you will be approved, just contact me.