WebRequest/Response ... How can I detect download speed?

Hi there,
Here's a problem that I've found absolutely no help online or on MSDN with. Maybe someone can shed some light on this subject.
I have an application which downloads files from a web site. Everything works great. I would just like to implement a status label showing the download speed.

Here's the code for downloading the remote file and saving to a local file.

         HttpWebResponse resFile = (HttpWebResponse)reqFile.GetResponse();
                    // Once the WebResponse object has been retrieved,
                    // get the stream object associated with the response's data
                    remoteStream = resFile.GetResponseStream();

                    // Create the local file
                    localStream = File.Create(locFilName);

                    // Allocate a 15MB buffer
                    byte[] buffer = new byte[15360];
                    int bytesRead;

                    // Simple do/while loop to read from stream until
                    // no bytes are returned
                    do
                    {
                        // Read data (up to 15MB) from the stream
                        bytesRead = remoteStream.Read(buffer, 0, buffer.Length);

                        // Write the data to the local file
                        localStream.Write(buffer, 0, bytesRead);

                        // Increment total bytes processed
                        bytesProcessed += bytesRead;

                       // Update progressbar
                        this.Invoke(new updProgressDelegate(this.updProgress), 1);

                    } while (bytesRead > 0);