Is it possible to let your user download a file with a different name?
For example, there is a file called "4324ffsd34.jpg". I want people to download it via download.php, with a different name (like "filetodownload.jpg"), without renaming the original file.
Sure, use a Content-disposition header
header('Content-Disposition: attachment; filename="filetodownload.jpg"');
if you wish to provide a default filename, but not automatic download, this seems to work.