Add item help to label using title attribute

Here is how you can add item help using title attribute to APEX form items.

First create application process GET_ITEM_HELP:

DECLARE
  l_sql VARCHAR2(32700);
BEGIN

  l_sql := '
    SELECT item_name,
      item_help_text
    FROM apex_application_page_items
    WHERE application_id = :APP_ID
      AND page_id = :APP_PAGE_ID
      AND item_help_text IS NOT NULL;
  ';

  APEX_UTIL.JSON_FROM_SQL(l_sql);

END;

Add to page JavaScript Execute when Page Loads:

$.ajax({
 type:"POST",
 url:"wwv_flow.show",
 dataType:"json",
 data:{
  p_flow_id:"&APP_ID.",
  p_flow_step_id:"&APP_PAGE_ID.",
  p_instance:"&APP_SESSION.",
  p_request:"APPLICATION_PROCESS=GET_ITEM_HELP"
 },
 success:function(jd){
  $.each(jd.row,function(i,jr){
   $('label[for="' + jr.ITEM_NAME + '"] span.jelp').attr({"title":jr.ITEM_HELP_TEXT});
  });
 }
});

Copy your Optional label template to new name. Change Before Label definition:

<label for="#CURRENT_ITEM_NAME#" tabindex="999"><span class="optional jelp">

Change your form items use new label template and write help to item Help section.

Run page and hover mouse over item label.

Update 26.01.2012

On APEX 4.1 you do not need extra application process or JavaScript. You can just modify label template as below

<label for="#CURRENT_ITEM_NAME#" tabindex="999"><span class="optional" title="#CURRENT_ITEM_HELP_TEXT#">

Thanks to Peter informing that there is #CURRENT_ITEM_HELP_TEXT# substitution string available for label template.