Ok, I'm doing a project in school where I contact airlines (if you want to see it, go to the site mentioned in my profile). The end of the year is rapindly approaching. I might get some of my friends to help me organize my collection. I'm starting to make the database for it, but I need help setting categories. I've received postcards, safety cards, letters, mousepads, lanyrads, calendars, IF magazines, airline overview magazines/brochures, model planes, keychains, paper tags, luggage tags, a hat, and a backpack so far. Should I organzine them by airline or product type? I was thinking flat things like postcards and safety cards I will keep in a folder or something.

Feel free to tell us how you organize your collection.