Minecraft Premium User
This adds permission to users to post in new places after they check that they are a legitimate premium Minecraft user.
The plugin adds a page where forum user can verify their minecraft account. Then the minecraft account is sent to minecraft.net to check if they are a premium user. If they are premium users, the username is stored in the MySQL database and the plugin "promotes" user into a group named "Minecraft" which you can customize and make additional forum just for those groups.Then, the minecraft username is also shown in the postbit.
Support
http://community.mybb.com/thread-114228.html
Changelog
http://mods.mybb.com/change-log/minecraft-premium-user