Instead of doing it the traditional way with pieces of paper, you can use this app to avoid getting yourself, or have closed loops. No need to be on the same place, same room just to organise this either.
Create a group, add each participants name and email and viola! It's done.
Note: You have to become an 'elite agent' if you want to create a group larger than 4. Otherwise, you can use it for free as long as you like :)