from my controller I want to assign a value to an application variable much like I would a session variable.
I assumed I could just use:
Application("MyValue") = "test"
HttpContext.Application["MyValue"] = test
If you are trying to use this to pass data from the controller to the view, use the ViewData.
ViewData("MyValue") = "test"
If not, please give more context as to what you are trying to accomplish.