What would be the fastest way to concatenate three files in C#?

Question

I need to concatenate 3 files using C#. A header file, content, and a footer file, but I want to do this as cool as it can be done.

Cool = really small code or reall

Answer 1

Another way....how about letting the OS do it for you?:

ProcessStartInfo psi = new ProcessStartInfo("cmd.exe", 
        String.Format(@" /c copy {0} + {1} + {2} {3}", 
            file1, file2, file3, dest));
psi.UseShellExecute = false;
Process process = Process.Start(psi);
process.WaitForExit();