I find that all links to images and other files end up with absolute URLs in the HTML. I gather you can stop this from happening. Is the best way to do this to go to
Admin > Content Administration > File Upload Preferences and simply change
URL of Upload Directory http://mysite.com/images/folder/
to
URL of Upload Directory /images/folder/
Is that the way to do it, or does that need to be a full URL on that preferences page?