I'm looking for public web services

Do you know of any?  I'm compiling a list of public services one can use in their own applications.  I am looking for anything of value that is consumable.  I would prefer they have some sort of government focus or benefit.  It would also be nice if they are SOAP based web services.  However, an example of something that isn't SOAP based but still consumable and programmable without having to do "screen scraping" is the homeland security alert level url https://www.dhs.gov/dhspublic/getAdvisoryCondition.  Weather and geocoding are other examples.

If you have any, please post the url in the comments section.  I will start a list over on https://www.federaldeveloper.com.  Thanks.

-Marc