[brianogilvie]

When you check an item, it doesn't disappear until you use the Clean Up command or change your view settings or perspective. Even then, it is not deleted; it is just hidden unless you have your view bar set to show All or Completed actions.

When I go on a trip, I use such a list in OmniFocus and check off things as I do them or pack them. My list includes things like setting an out-of-office email if appropriate, and turning off the main water valve in the winter, as well as packing. When I'm done and all set to go, I select the project, show completed items, select them all, and use the contextual menu to mark them uncompleted, so I have the list to complete the next time it's necessary.