AddComponent with runtime type checking

I'm trying to add a component from a string at run-time (I have component names stored in a simple XML file).

I'm trying to do something like this in C#, but it dies with "The type or namespace name "T" could not be found"

 Type T = Type.GetType(compName);
 T x = myObj.AddComponent(compName) as T;

What am I doing wrong?