How To: Write a text file to the Output Stream?

Ok, I know how to create a text file on the system and write text to it, but what I would like to do is write to a new file and never store it physically, but just write it to the output stream for download.

 Can someone give me a VB example please?
1 ' Eliminate this part
2 Dim FILENAME as String = Server.MapPath("Output.txt")
3
4 'Get a StreamReader class that can be used to read the file
5 Dim objStreamWriter as StreamWriter
6 objStreamWriter = File.AppendText(FILENAME)
7
8 'Append the the end of the string, "HELLO: "
9 'followed by the current date and ...