In addition to the standard meeting roles, Clubs are free to define their own special roles.
Some clubs, for example, have a "Joke Master" that tells or asks people to tell jokes to break the ice and to practice one of the most difficult but useful tools of public speaking - humor.
Some clubs have language games for helping members improve their control of the language, and they have a role called "Game Master" that is the person in charge of organizing the language game session for that particular meeting.
If you have nonstandard roles, please make sure that either the Meeting Leader or the people in charge of these roles explain their purpose at the beginning of the meeting, for the benefit both of guests and new members that might not know what these roles are about.
You don't need to ask permission from anyone to have a special role in your club meetings - just go ahead, test the waters and see how it works. If it does, please share your idea with the rest of the community, so that all clubs can benefit. Also, if you define special roles, you don't need to have them in every meeting.
Whatever roles you want to define, never lose sight that the main goal of Agora Speakers is mainly educational, more than social. As such, any and all activities must be geared towards the education of members.
Also, be careful of not overloading the meeting with too many things. Meetings longer than two hours tend to become boring very quickly. If your meeting is too long, you may start seeing people (especially guests) leaving in the middle of the meeting, which can be very damaging for the overall enjoyment and morale, not to mention very distracting.