I see you've already declined this, but I'd really like to urge reconsideration. Seems to me the biggest advantage of an app over just a set of static, paper lists is the ability to use logic based on weather and destination data to modify the list. Suppose, for example, users could set a condition for "Bathing Suit" to appear on packing lists only when the forecast calls for temperatures over - say - 70 degrees? Since you say you ARE considering another excellent suggestion to invert the data structure - starting with items rather than activities and allowing those items to be assigned to multiple activities - then isn't this request just an extension of the same thing? Using items as the basic unit of information and giving them properties? If you start with - say - "Sunglasses" and let the user give that item the property of appearing in both the "Beach" activity and the "Skiing" activity... then couldn't it have other properties as well? It would certainly be more helpful than a paper list if I could set "Snorkeling Gear" to be included when I'm going to the Bahamas in 80 degree weather, but excluded when going to Omaha in -20 degree weather.