I was cleaning my kids' rooms and kept finding flash cards and card games EVERYWHERE!! So, I found an empty box and just started collecting them as I went about my cleaning. When I was done, I was left with a bunch of cards from several different sets...many with no boxes or ones that were so ripped they were useless. I've rubberbanded them together before, but they NEVER end up back together when the kids are done. Over at Brown Paper Packages, I saw a cute Book on a Ring (which I LOVE) and decided to adapt it in order to find a solution to my problem.
You will need your cards, a hole punch (I recommed a Crop-a-Dile if you have one), a marker/pencil, and Album Rings (I used 1 1/2").
Mark the corner of your card so that you know where to punch. Make sure not to punch any words!
Use your hole punch to punch the first card. It then becomes your template to punch the other cards. The crop-a-dile EASILY punches 10+ cards at a time, so feel free to stack them together (making sure they are all lined up the same way).
Put your cards on the ring and you've got one set of cards, all nice at neat!! I did this with flash cards AND games. I plan on keeping the flashcards on the rings and just flipping through them. However, the games (such as matching or memory games) can be taken off and then put back on the ring when you are done playing with them. For now, I just have all the rings of cards in a plastic storage container. Eventually, I have visions of a peg board where they can be hung in reach of the kiddos!