German city Munich got itself into the American newspapers a few years ago when the city council decided to start the project LiMux, aimed at gradually banishing Microsoft programs from the town hall computers & introduce Open Source software like Linux & Open Office onto all town hall workstations. This project was so succesful, other local authorities in Germany have now followed suit.
Many German cities, the German Foreign Office & the Office for Information Security (BSI), are putting their trust in alternatives to Windows, Word & Excel (Microsoft Office).
Here's some explanation regarding the LiMux Project:
What is LiMux?
Status quo of the LiMux project:
Here you can read more about the Munich LiMux project.
Here is a case study on the website of the Open Source Observatory and Repository.