you could redirect it to another image, a 1k gif with your url...
Funny, I noticed someone using Getright on one of my sites tonight and I decided I wanted to do more than just block them so I wrote a little CGI script that creates an image with their ip and a 'please fuck off' message for them to download instead (
http://jamess.boxx.ca/cgi-bin/fuckoff_leecher.cgi ). I wouldn't use it against hotlinkers though as it would still suck up resources and bandwidth.
cheers