If ReCreate is in the US, he's probably indisposed with Thanksgiving.
It looks like I have it backwards. If no headers are included, the file is not cached. I built a PHP application that does something similar (serves randomly selected images). Returning an image boils down to this...
header( "Content-type: image/jpeg" );
@readfile( $ImagePath );
...where $ImagePath is... I'll let you guess. 