If you use XML literals in your code, adding one to another: Dim e1 = <a:books></a:books> dim e2 = <a:book></a:book> e1.Add(e2) You will have the xmlns declaration repeated in each of the elements, when really it is only needed...
I just finished writing an article about Expression Trees for Visual Studio Magazine (aka VBPJ ) and there seemed to be some "holes" that I think should be plugged. An expression tree is basically a descriptive way of representing a lambda function...