Über dieses Add-on
Firefox 2 and up will save your dog ear locations for individual URLs.
Please note that using Shift+Click to mark the page will not work if you are clicking directly on text. This is intended to avoid conflicts with the Firefox default action of highlighting text.
Also, if you would like to help beta test, I am constantly uploading beta versions of Dog Ears to my home page (http://yellow5.us/firefox/dogears/)