Sending HTTP Requests from a C# program seems unnecessarily hard.  I wrote a small helper class to deal with sending and timing GET requests:
http://www.goldb.org/httpgetcsharp.html

You use it like this:

 public class Program { static void Main(string[] args)
{ HTTPGet req = new HTTPGet(); req.Request("http://www.google.com"); Console.WriteLine(req.StatusLine);
Console.WriteLine(req.ResponseTime); } }