Thanks very much for all the replies! Yes, I am using mod_perl and so it looks like in my case using a temporary file is the best approach. I just needed confirmation that I wasn't missing something.

Thanks also for pointing me to "sendfile()". Somehow I had not seen that before. On a previous web site I read the file chunk by chunk and wrote it out manually in a loop. sendfile() or Slurp looks much easier. These files are only small images so no need to do anything else. On the other site I did, they were downloading files that could be over 100MB!

Thanks again...