Just saw this information today. For anyone interested, event is happening this weekend (starting Friday evening).
http://seattlegov.startupweekend.org/
April 27 - 29, 2012
Seattle City Hall
600 4th Ave, Seattle WA
Crunch government datasets, improve public safety, and work alongside your local government officials at the first-ever Startup Weekend GOV at Seattle City Hall, April 27-29th, 2012.
Startup Weekend is an intense 54 hour event which focuses on building a web or mobile application which could form the basis of a credible business over the course of a weekend. The weekend brings together people with different skillsets - primarily software developers, graphics designers and business people - to build applications and develop a commercial case around them.
Tickets are still available, but Startup Weekends almost always sell out. Sign up today!
Everyone can participate! Even if you cannot make the weekend, browse available open datasets and submit your ideas (or vote/comment on existing ideas) at http://opennw.ideascale.com