May I suggest something which is somewhat related: The “Tip-of-the-Day”.

* It should be ON by default;
* It should have a check-box titled “Do not show…”;
* The Help sub-menu should have a setting “Turn ON the ‘Tip-of-the-Day'”;
* It should preferably explain tricks not that obvious;
* It should NOT duplicate help items. These are searched for anyway…
* On the release of a new version, the tips should be about the new features;

I am sure that these forums provide a wealth of non-obvious usage of EE!