I looked back into the pictures from the years past. On a whim, we did a poster based on the OLPC Austria design. We left the inside blank, in the hopes that the community would come and fill it. And fill it, they did!
Here are the posters from 2010, 2011 and 2012. We'll have one this year as well. Be here and personalize it! http://olpcsf.org/summit