mod_rewrite wackiness

So, in my last post I was writing about using mod_rewrite to send people to another image. My initial thought was to just send any image request that wasn't from my site to an alternate image. The first problem I had was the image I redirected to was caught by my rule also (which created a nice loop). Then I realized something else. If I did it this way, people reading my site via RSS wouldn't be able to see images. And also, people reading this via LiveJournal would have the same issue. So in the end I'm going to just add sites that leech images from me as they do it.