There are several steps to creating a custom web service to be hosted in SharePoint. The MSDN library has a walkthrough on creating a custom web service. After having followed this walkthrough thoroughly, I though my web service was good to go. Unfortunately all I saw was an error: “Could not load type ‘ThisAndThat’ from assembly ‘SoAndSo'”. Just as I was about to search for an answer somewhere online, I remembered that the MSDN library features the Community content for little over a year now (hooray!).

At the bottom of the walkthrough were some community additions to this specific walkthrough. Some have been incorporated in the main article, others are there to be found for guys (and girls!) like you and I. One of them exactly described my problem. In that same community content item another user had added this comment:
HI – I resolved this issue with a service by prefixing the class name in the .asmx file with the assembly namespace
And that was it! The WebService works like a charm, hosted in SharePoint. (hooray!)

So there you have it: that’s the power of [wikipedia:web 2.0] for you. Users benefit from the fact that they are now able to add to the otherwise pretty static information in something like the MSDN library. ;)