Hi,

>Thanks for the link Tracy. He sure seems to indicate that there are no performance problems, although as Viv mentioned, he doesn't show the code he used for his benchmark test.

I don't think there should be a performance issue. Given:

   public static class MyExtensions
    {
        public static string AddOn(this string s, string s1)
        {
            return s + s1;
        }
    }

then

string str = "Hello".AddOn(" Fred");

is just syntatic sugar for

string str = MyExtensions.AddOn("Hello", " Fred");

i.e. as far as the compiler is concerned they are identical