Christmas List Organizer is a simple iPhone application that will make Christmas Shopping easy for you. Simply list the people you want to buy presents for, enter about how much money you want to spend for that person, then specify the presents you want to get them, and what store you expect to buy each gift. When you buy the present you check it off and enter the actual cost. The app will calculate the amount you have spent on each person, and will change the background to green when all the presents for that person have been bought.
A great feature of the app is that after you have entered the presents and the stores, you can go to the Stores screen and click on a store to see all the presents that you have listed for that store, and check them off as you purchase them.