Hack de Overheid ('hack the government') is a one day event that brings civil servants together with coders to discuss Open Data issues, as well as build applications during the day.

The first event was held in Amsterdam, Netherlands on June 13th 2009. Organized by James Burke and Lex Slaghuis, as spin-off of the work Ton Zijlstra and James Burke were doing for the Dutch Ministry for the Interior on Open Data.
Now Hack de Overheid is also a 'for-hire' event that you can add to your own conference or event. For instance during the yearly Dutch Digital Conference in November 2009, Hack de Overheid live coded open data applications at the conference venue and presented the results at the end of the day.

Website: http://www.hackdeoverheid.nl/
For more info contact James Burke