This addon provides a Shopping List that your customers can use to keep track of items that they want to reorder periodically, or that they want to save for a future order. It was designed for an osCommerce store that sells consumables, but it works with any type of business that wants to increase repeat business.
Your customers can create multiple shopping lists, up to a maximum that you set in your store's Admin. Products can be added to a shopping list from a product page or from the shopping cart. Any product in a shopping list can be added to the cart, or the whole list can be added at one time. There are a full set of features that allow your customer to create, modify, delete, and view their shopping lists.
Support thread: http://forums.oscommerce.com/topic/397359-addon-shopping-list/