You can also effect the same thing with the HEAD method (instead of GET)

Debug.WriteLine("GET");
//GET
WebRequest r = HttpWebRequest.Create("http://dotnet.org.za/MainFeed.aspx"">http://dotnet.org.za/MainFeed.aspx");
r.Method = "GET";
WebResponse p = r.GetResponse();

Byte[] bytes = new byte[1000];
int res = p.GetResponseStream().Read(bytes,0,1000);

Debug.WriteLine(res,"bytes read");
Debug.WriteLine(p.Headers["Last-Modified"], "last mod");
Debug.WriteLine( UTF8Encoding.UTF8.GetString(bytes),"body");

Debug.WriteLine("HEAD");
//HEAD
r = HttpWebRequest.Create("http://dotnet.org.za/MainFeed.aspx"">http://dotnet.org.za/MainFeed.aspx");
r.Method = "HEAD";
p = r.GetResponse();

bytes = new byte[1000];
res = p.GetResponseStream().Read(bytes,0,1000);

Debug.WriteLine(res,"bytes read");
Debug.WriteLine(p.Headers["Last-Modified"], "last mod");
Debug.WriteLine( UTF8Encoding.UTF8.GetString(bytes),"body");