The wonderful flexibility of a ring-binder system extends beyond how you use it, to how you archive it too. For many people it makes sense to archive pages by year. If you haven't seen Patty's post on 20 years of her archived pages, go read it! It's amazing!
But for some people, it makes more sense to archive pages in other ways besides by calendar year.
For students, teachers and parents of school kids it is convenient to archive by academic year. That way all of your relevant class, activity and contact information for that school year is all together in one book.
I move internationally often, and the moves usually happen in the spring or summer so they don't correspond to the calendar year. So I archive by location. For example, we lived in Indonesia for 15 months, and all of my Indonesia-specific information is archived in one binder.
Similarly, you can archive travel information after your trip so all your destination-specific details, reservations, packing lists, leftover currency and coins, and local contacts are kept together. Then if you return to that destination all the relevant information you need is easily accessible.
When working on a big project, you can archive all the information relevant to it in one place. That way you have the entire timeline and related information stored together for easy future reference.
Do you archive your pages in a way other than by calendar year?