From OSGeo Wiki
OSGeo and the OReilly OSCON event.
OSCON is the crossroads of all things open source, bringing together the best, brightest, and most interesting people to explore what's new, and to champion the cause of open principles and open source adoption across the computing industry.
OSCON 2008 is happening July 21-25 in Portland, Oregon. Join over 2,500 open source developers, hackers, experts, IT managers, and users at OSCON 2008. This year's convention will include 40 tutorials that go deep into open source technology and over 400 sessions focusing on Administration, Business, Databases, Emerging Topics, Java, Linux, Mobile, People, Perl, PHP, Programming, Python, Ruby, Security, Web Applications, and much more.
OSGEO Cascadia handled the booth.
Read more about OSGeo at OSCON 2006.