I don't have a 3 ring binder, but I do have an expandable folder/organizer where I store all my Disney stuff.
http://www.staples.com/office/suppl...ess_Supplies_0_10051_SC1:CG15:DP1458:CL141235
We had 4 trips planned this year so it was a LOT to keep track of.
Inside I have a folder for each month we have a trip planned. I put the reservation confirmation, airline e-tickets, confirmation of my owner's locker order, my grocery list/confirmation, any receipts for hard ticket events, etc.
Then I have a folder each for general stuff:
my owner's locker order form, terms and contents;
Southwest Rapid Rewards info;
general contact list (which has our bank phone #, insurance co's, car dealer (in case the car doesn't start when we get home),
DVC member number,
doctor phone #'s,
pharmacy that delivers to WDW resorts,
parents/neighbors phone #'s (they are all in my blackberry, but if my battery dies or I lose my phone, I'm dead!!),
Car service phone #
Credit card phone #/account#
I bring the whole binder in my carryon so I always have all my info with me. Its also all in my laptop, but again, if that is not available, crashes or doesn't make the trip, I have everything still available.