Using Reflection to load unreferenced assemblies at runtime in C#

Sure, we can define our application's referenced assemblies easily, but how would we interact with types in assemblies at runtime that we don't directly reference? This can be quite a problem for someone who is creating plug-in or add-on support for their application, where the assemblies they must reference will be added post-build. One of the functions of the System.Reflection namespace is loading assemblies and accessing their contained types.