Interesting topic Tedndrake, they do get all over the place, I hope you were able to put them down since your post. I just use the plastic containers from take out Chinese food. Once they are out of the plastic tube, I don't even try to put them back in, but that's just me. I used to just keep them in a plastic bag, sometimes  I use zip lock bags, I like to be able to see them before I reach my hand in. But I guess you need a place that has good take out.
Perhaps there is a better suggestion out there.

I've found that "Tupperware Hot Dog Keepers" work great for R&F Pigment Sticks.  They're pretty air-tight, they keep the paint sticks separated (clean) and they're relatively inexpensive.  I bought several on eBay.

I use the plastic tubes they arrive in. They slide in and out easily. When the stick is getting smaller, thereby making a longer section of empty tube, I just use a pair of scissors to cut the tube back. It's easier then you might think.

At one point I tried keeping the caps on to see if the skin would come back more slowly. It did not seem to matter. As long as the tubes are stored in still air, the cap makes no difference. I'd probably use them if I traveled though.