I found that if I created a FileStream I could use the byte array already defined (using your code) to save the PDF. For anyone who might need this solution, below is the code I used for the PDF saving portion.
// code snippet with the first two lines taken from Peter's tutorial, illustrating where b and len used in the FileStream came from...
byte b = memStream.ToArray();
int len = b.Lenth;
FileStream fs = File.OpenWrite(Server.MapPath("~/myPDFlocation/myPDFname.pdf));
fs.Write(b, 0, len);
Response.OutputStream.Write(b, 0, len);
// close the previously defined MemoryStream used to output the iTextSharp created PDF to the browser