This solution consists of 3 projects. The 'BasePlugin' which defines the interface of which plugins are to build upon, a 'Plugin' that implements this interface, and the 'Plugin Loader' application that loads the plugin dynamically.
This simple example just does a simple 'Hello' message from the plugin, but I was trying to keep it as simple as possible. The concept of a 'plugin' type nature may sound a bit tough to pull off, but due to the .NET runtimes Reflection namespace plugins are something that are EASY, if not trivial, to accomplish.