Some ideas about designing a poster:

1) design something that will look good large or small - as a full sheet of paper, as a half-sized sheet, or as a double-sized tabloid.

2) make the most important information the most visible -- in the example below, the relief agencies, the tellers' names, and the date time and place stand out equally well.

3) don't be afraid to include lots of information for people who are really curious but need to know more.

4) The logo uses Papyrus font for the heading -- you could use some of that in your own design, but you'll also want a more readable font for the heavy duty business of conveying information.

Here's an example of how the Odyssey Storytellers of Ithaca, NY used the materials to make a flyer for their own Story Tsunami event.