How can I display topic posts as "last post first" the way forum topics are displayed. Can't find this VERY useful option anywhere?

Do you mean when you come from day to day?

Like since the last time you were here?
If so then click View new posts on the top.

Tech, no not day to day. I wasn't clear, I mean, that within a topic thread the newest post would always be shown at the top of the topic thread page.
Some forums show "last/newest post first" when one logs in. This is especially nice in long threads - once the topic thread is hit the first post comes up automatically and then as one scrolls down those are progressively older.

(For example the ClubLexus forum allows the thread sorting option to be selected once logged in and retains it. It is just a more logical approach to reading, imo.

FROM THE CLUBLEXUS www.clublexus.com Thread Display Options Help Page (once logged in):
"What are the various thread display options?
When viewing a thread, you will be able to view the thread from a choice of four modes.
Linear Mode (Oldest First) - In this mode, posts are displayed chronologically from oldest to newest. Posts are shown in a flat mode so that many posts can be viewed simultaneously.
Linear Mode (Newest First) - This is the same as the above mode, except that posts are ordered in an opposite way (newest first).
Threaded Mode - In this mode, a tree is shown along with every post. This tree allows you to see the relationship each post has to others, in terms of who responded to whom. Only one post is shown at a time.
Hybrid Mode - This mode is a mixture of the linear and threaded modes. The post tree is displayed like in the threaded mode, but multiple posts are displayed simultaneously like in the linear modes.")
[emphasis added]

Maybe this option is in "My Asssitant" as a forum control on the login line but I don't seem to have access to that, maybe cause i'm a noob! :)

I haven't really checked or noticed what you are asking but I will send a PM to the Admin and ask him to ring in on the post and answer your quiestion.

And another thought, from a forum marketing perspective, "newest post first" keeps all the ads at the top of the form for people to see, as they are reading the latest posts.
As I am reading this forum I am always sent to the end of the thread at the "bottom" of the form where there are no ads, why not just reverse the post order as the default once logged in, as there are no ads in this view as I read this thread at the bottom?

I PMed Admin still waiting to hear about it.