Memistore is a great little device that connects to your camera’s 1/4-20 mount or hotshoe and holds two SD cards. I love the idea of having a couple more of these at the ready. The battery lasts, but the memory card runs out quick, especially when shooting video. The Memistore is also splashproof, so you don’t need to worry about a little water. You can get one for a pledge of about $15.