Disney has announced a watch and litho of POTC 3 that will be available at the resort starting March 20 and ending August 18 (or until supplies last). A set of one watch and one litho are available for $10 (plus tax) with the purchase of $50 (before tax and after discounts) or more in a single transaction at participating resort merchandise locations.
The wording would seem to indicate that you can buy one set when you spend the qualifying amount but not necessarily that you can buy two sets if you spend $100. Previous promotions have differed in how they handled that.
For more information, pictures of the watch and litho and a list of participating locations, go here.