Did you already see the region type called "Help Text"?
If you don't like to write documentation, this feature is something you should look at. Of course we all start with writing our test cases and documentation about how the system will work before we actually develop, so not sure who will use this ;-)
Seriously, some of us do put some help text with the items, so if you click on the label of the item you get some help. Wouldn't it be nice in that case if you could also see the help of all items at once?
That's exactly what this new feature is doing! The Help Text Region gets filled with all Help Text of the items on that page.
An example will make it more clear...
1) Create a new Blank Page with as template "PopUp". On that page create a new region of type "Help Text". (see the above screenshot to select the region)
Give it an alias of HELP_PAGE (in Page Attributes)
2) On another page, create two new items: for ex. two text-items: name and address and add some text in the Help section. Also add some text for the Help in the Page Attributes
3) Last step to do: add a url to the Help page on every page
Go to page 0 (create Page 0 when you don't have it) and add a region (display before footer) with a link to f?p=&APP_ID.:HELP_PAGE:&SESSION.:&APP_PAGE_ID.
Also put a condition on the Help Region as we don't want to see the help on the help page itself.
("Current Page is NOT in Expression 1")
An export (APEX 3.1) of an application which shows this feature in action, can be downloaded here.