Create class from type and use it as a method's inputting generic class

I have a method like this:

public T GetDataObject<T>(int id) {
   ...
}

Now I want to invoke this method based on a type, like I have some code that does this:

var typeStr = String.Format("{0}.{1}, {0}", Properties.Settings.Default.ObjectNameSpace, Request.QueryString["Type"]);
var type = Type.GetType(typeStr);

the typestring can be anything, I want to keep it generic like this. So how can I invoke my method based on this type?

I know this doesn't work, which makes sense, but it gives u an idea of what I want to accomplish:

var obj = GetDataObject<type>(Convert.ToInt32(Request.QueryString["ID"]));

Any ideas?