Step 1: After logging in, click the User Control Panel link.
http://i.imgur.com/R1CHOfW.png

Step 2: Click the usergroups tab.
http://i.imgur.com/RTKjHFZ.png

Step 3: Click the "Select" bubble for the General Public usergroup.
http://i.imgur.com/WHLjb0s.png

Step 4: Scroll to the bottom, make sure "Join Selected" is selected in the drop-down box, and click Submit.
http://i.imgur.com/ICi8GF6.png

Congratulations! You are now a General Public member and can start new topics. Also if you want to make your name gray to indicate this, repeat steps 1-4, but instead of clicking the Submit button on Step 4, click the Change Default Group button on the left.
