It was great to find out about the different kinds of collaborations that are emerging between Wikipedia and other open knowledge projects. As the projects grow and their databases become more complex and rich, members of the communities have been experimenting with different ways of integrating their data, creating interesting mash-ups. For instance, the integration of data from Wikipedia and OpenStreetMap (OSM) could be understood as a mash-up of an encyclopedia and an atlas. A truly open and free knowledge mash-up.
The creation of the WikiMiniAtlas allows Wikipedia users to see a draggable, zoomable, and clickable map (rendered with OSM data) when they are reading articles with geocoded information such as the ones about cities, monuments, and buildings.
On the top of the article, in the right corner, users can now find an icon of the world near to the geographic coordinates. When this small icon is clicked a map pops up and can be moved around the screen.
Another interesting project that mash-ups Wikipedia and OSM is WIWOSM. 
This project shows geometric objects (lines, polygons) from OSM in the Wikipedia article creating more clear visualizations of complex geographical objects such as rivers, streets, and districts.
As a contributor of both, Wikipedia and OSM, I was happy to see how the two projects are being integrated, and by extension, to confirm the creative and innovative potential of non-proprietary and non-market cooperative initiatives. Confirming the potential of the peer-based mode of production of information, knowledge and culture, by meeting active peers “in person” was one of the highlights of Wikimania 2012. The ethos of openness and collaboration was celebrated by sharing stories of successful projects, visions of future initiatives, discussions about cultural and social practices, and critical research findings. I am looking forward to assisting to the next Wikimania.
