what i did when i was getting hotlinked from one of those hotlink pic post bulletin boards is instead of a url i put a pic up there for them
RewriteRule (gif|jpg|png|swf|mpg|avi|GIF|JPG|PNG|SWF|MPG|AVI)$
http://www.mydomain.com/spam-pic.jpg [R,L]
the pic had my logo on it and it said
"daily updated free porn. hand picked, surfer friendly free porn pics, vids, stories and live cams. over 1 million visitors a week cant be wrong!"
they removes your links in a hurry when you do that. havent had any problems since.
p.s. i dont really get a million visitors a week
