The idea of an InstallFest has been raised a few times, but the when, where and how are sort of vague.
In order to reach the unwashed masses, flyers for laundry rooms, community centers, library bulletin boards, restaurants, etc. See http://wiki.softwarefreedomday.org/StartGuide#Useful_Documents.2C_Templates.2C_Files_and_Examples and http://spreadubuntu.org/
There was some brainstorming post-meeting last month. See the end of the full IRC log.
Coordinating people's time and resources...