Another benefit of my participation to FOSS4G-NA 2012 was learning about GeoTrellis, an open source geographic data processing engine for high performance applications.
From the website: "GeoTrellis accelerates geoprocessing tasks by harnessing the power of multiple cores, processors, and servers through distributed geoprocessing. By breaking large or complex tasks into smaller units of work and optimizing their execution, the framework can concurrently leverage massive computational power to produce results 10-100 times faster than traditional geoprocessing software. [...] Faster is not just faster, it’s different. For example, a truly responsive user experience makes it possible to create public participation planning tools or educational games that incorporate sophisticated geospatial models."