I was just using empty photo inserts that came in a couple of wallets. This wasn't ideal, it still left me fumbling and then having to remove the card from the sleeve, etc. So today I decided to hole punch my cards and store them on a key ring. Yeah you will still have to flip through them, but there really is no avoiding that. However, once you find your card you can just hand it straight to them. Plus, this takes up like no space.
I slid this down in a side pocket in my bag to keep it out of the way. I'm really pleased with this idea. Recommendations: hole punch each card individually, paying attention to bar codes, magnetic swipe strips, account numbers, etc. All your cards don't necessarily have to face the same way, and if you remove an important part of the card it's basically useless. Also, don't punch too close to the edge. You want it to be sturdy and not break off. I didn't store any paper cards on this, only plastic.
Hope this helps! Muaahh!