I also have gone the same route as Joel....I lOVE the zippered binders!
Chips can't get too lost and they have nice inside pockets (I store empty extra flips there). I prefer the Mead brand 5-Star binders. They usually go on sale late summer at Walmart before school starts in a nice assortment of colors (I have green for Vegas, black for Colorado, etc) , and I have even picked up 2 new/unused ones at our local Goodwill thrift store ($1 each).
So far they have held up extremely well...