Key Smarts are my preferred key holders, easy to fit in your pocket, keys are easy to fold out. You do have to give a little thought on how you want keys arrange, due to different size keys, they are a bit annoying to assemble, but worth it. Also recommend getting the expansion pack with it.

I bought this to organize my work keys, specifically Medco keys, and they are too big to allow the keys to fold into the middle. Also, when I try to flip one key out, I have to hold the others, as well as the little clip piece down otherwise they all spin. Compact, sturdy, and time will tell how durable.

I used to strongly dislike walking with a dangling set of keys making that unpleasant noise so I am really glad I tried Keysmart and it has definitely solved that problem along with a couple of others like easy management and compactness. I do sometimes get a little frustrated when my hands are full of grocery bags and I am trying to poke out the right key and it takes 5 seconds. I bought two more as gifts for my friends.