I stumbled across NOAA's SOAP Service and it got me thinking. What other eGovernment services are provided to Business and the general public by Governments? I know the United States has a lot APIs, but what about other governments like the European Union. I am interested in not just SOAP but any Remote Procedure Call (RPC) service available to the public over the internet. I am interested in more than just data sources, but other types of APIs as well.
I started compiling an answer with a list of APIs per countries, but I realized I wouldn't have the time so here's already a few pointers.
I am making this answer a community wiki so others can contribute directly. I think this is a very good question and it deserves a very comprehensive answer and that we consolidate this stuff in one area.