Check out the Automatic Record Numbering video.

If Kevin's suggestion doesn't work for you, let me know. Might make an interesting video.

If your list box's row source type is "Field List", you can't change the order because the table or query specified in the row source sets the order. But if row source type is "Value List," you can do it with VBA.

On a "Value List", the row source looks something like "Apple;Boy;Cat;Dog;Egg". Turn this string into an array with the Split() function. E.g. arr = Split(ListBox.RowSource, ";"). That makes arr(0) "Apple", arr(1) "Boy", etc.  To move the 4th item up one spot, you just swap the 3rd and 4th items: s=arr(3): arr(3)=arr(4): arr(4)=s. Then you use Join() to re-connect the items: Me!ListBox.RowSource = Join(arr, ";"). No need to requery the list box. But you do need to unselect the item with VBA: Me!ListBox=Null

When the user selects an item on the list box, the list box's AfterUpdate event is run, and the selected item's position is ListBox.ListIndex, assuming multi-select is disabled. The positions are 0, 1, 2, etc. from top to bottom. If no item is selected, Listindex is -1.

What Rabid said is true. If you do have a field list, you can just add a "sort order" field to that table and manipulate it with a little code. See Custom Sort Order. Like I said, this would make a cool little video. I'll add it to my list. :)