I really didn't know what to expect.
Information on the official site and wiki was limited. The location, percise problem definitions, available resources, what we should bring - all quite hazy.
I don't think I could be much happier with how it turned out.
Random Hacks of Kindness (RHOK) is a weekend-long event in dozens of cities that puts volunteer programmers to problems identified by disaster relief experts. In Seattle, this took the form of around 20 people going after (1) mobile damage assessment and (2) identifying and providing information on populated places during disasters. Splitting off into groups, I joined the group working on the latter problem.
A decent portion of our first day was taken up with research and getting set up. The problem asked to pull information from Wikipedia for the populated regions, but the GeoNames API was vastly more suited for the task. It was decided to create a very simple Rails app that took as its input a know populated place. The user would then be prompted with a disambiguation page that includes a search radius option. The final output drops some very basic data about nearby populated places (at the moment, just the name and population), hopefully later to be expanded (haven't quite gotten around to that).
Lion's share of the credit goes to Kevin Moore and Ezekiel for doing much of the hacking. Being fairly new to Ruby I mostly helped with the spatial stuff - talking up GeoNames, OGC, and database help at the end (and in some controller tests we never really used).
Source code is up on github here.