Alternative to Activator.CreateInstance

I've tried a few different ways to dynamically create an object of 'unknown' type. This is my final, simple result:

        public static T Create<T>()
        {
            Type type = typeof(T);
            return (T)type.Assembly.CreateInstance(type.FullName);
        }
</t>

Ok, I'm getting a little flak here. This is just a simple example. In my project I deal with a lot of data objects, not all know at compile time, as some classes / objects may be from other separate (dynamically loaded) assemblies, yet still within the AppDomain. A similar implementation of the code above allows my worker class to dynamically create any data object, and populate it. As far as code-costs go, this is a very light simple method. I'm still yet to check CPU-costs. If anybody has reliable stats on CPU costs please let me know.

        private static T From<T>(IDataReader reader, Type type)
        {
            dynamic obj = type.Assembly.CreateInstance(type.FullName);
            ...
            return obj;
        }

This code did / does not work for me as the compiler moans about the "new" keyword for the template "T".

object obj = new T();