The ones
Mamu suggested are particularily nice because the plastic case is just the right size to hold 3 atomizers for traveling. After cleaning, I line mine up in these cases to keep the in use atomizer neatly stored. A silica packet will also fit on top inside the case.
The Pit'r Pat cat treat/dog treat metal cases are nice too. They hold about 5 atomizers nicely.
For all your SD needs, you would find a lot of answers at Trog's forum. There's a list of suggested/recommended items.
ecigscrewdriver.com just click on forum and register.