With the price of quality SD cards dropping so low these days, I've aquired quite a few of them for devices ranging from cameras to audio recorders. This creates a problem of having to keep track of these tiny memory cards. Believe me, you WILL misplace one or more them eventually since they are barely larger than the size of a quarter. I've even found some of mine in the wash because I was using my pockets as a memory card case!
I finally got a better case and its from Pelican. Its about as bullet proof as you can get, is lightweight, looks great and is water resistant to boot! I've linked the case I purchased below.
NOTE: I also reccomend Transcend class 10 SD memory cards. They have been bullet proof and failure free for me, and they are extremely cheap! Usually about $1 = 1GB.