Looks nice, but there is one small niggle - you have:

use vars qw/ $VERSION @ISA @EXPORT @EXPORT_OK /;

@EXPORT_OK = qw/ file_handle file_name file_type mime_magic mime_type/
+;
[download]

However you neither require Exporter nor do @ISA = qw/Exporter/ so you will have trouble if someone does:

  use CGI::Upload qw(file_name);
[download]

Update Glad to be of help, only sad I've run out of votes today :)

/J\