When you inline an image, that reference acts as a referral to the image file, so outerlevel.com is referring me to http://outerlevel.com/blog/images/bullfrog128.png.

In the same vein, MySpace.com is referring browsers to those two image files. You can use this knowledge perhaps to block MySpace itself, or (and this is the more common version), to block everything that isn’t outerlevel.com or one of your other domains.

There’s a reasonably decent tutorial at: http://altlab.com/htaccess_tutorial.html

This is a very common solution. You can block the image completely, or replace it with a simple, very small image that says “This person inlined an image from outerlevel.com. How rude!”. Many sites get much much ruder with the replacement images. One I saw recently that was fairly clever was an image that was a few thousand pixels wide, which fairly severly broke most layouts.

googling “.htaccess image” will turn up lots of other examples and tutorials on how it’s done.