I have asked CamptoCamp for help on several issues regarding Swiss localisation, financial accounting, setting up Terp etc. They are very knowledgable and are part of the core developers in the community (e.g. see the many c2c_ modules), and very much open sourced oriented. They also have other special skills such as Geolocalisation and managed of hosted Linux environments
Openet, also based in Lausanne, are friendly and savvy, I've not yet worked with them yet though.