The following are some ways that you can gather guest lists:
1. Website Forms
Customised for your website or Guestlist requirements
Facebook Applications allow you to gather Guestlists from fans without then having to leave the fan page.
Promoters that you have added can make Guestlists for you via their pr.MyGuestlist website.
See - How do I add a promoter?
4. SMS promotions
You can send promotions or special events via SMS that patrons can reply to for attendance.
You can email with an event out so that patrons know to send an RSVP or to create Guestlists for that event.