Ran into a little problem hitting the memory limit for PHP when serving 100MB+ files through a script like:

$file = @fopen($filename,"r");

if ($file)
{
while(!feof($file))
{
    print(fread($file, 1024*4));
    flush();
    ob_flush();
}
@fclose($file);
}

Found that you need to call ob_flush() as well as flush() since flush() has no effect on the buffering scheme of your web server.

Just thought I’d throw that out there for anyone else.