Is there a programming option which would enable a highlighted icon (similar to what appears once logged into the index screen), indictating the last post read in a thread? If not already an option, this would be a great aid in tracking lengthy sequences. A button within the thread that could be checked, possibly.
[Edit: Just noticed the "Notify...posted" button. How does this option indicate a new post? I still think if this button indicates via messaging or email, that a colored icon based system would be more efficient.]