I mentioned this in another similar topic, but this is the topic I was originally looking for. Thanks to flash_gordon (I think) for pointing this topic out to me. I also am starting to accumulate some extra reflectors and P60 style modules, so this topic interest me and I have been keeping my eye out for storage solutions.
A good place to do this is when I'm trying to kill time in craft stores while my wife browses around, I try to find things I can use for flashlights, knives, etc.
Today I saw this storage container for $4.99 and it looked like it might work, so I gave it a shot, and it turns out it works perfect for my needs. I found this at AC MOORE near the beads. It's made to store beads in, and it's a case with 12 small containers inside that the P60's slide right into. They don't wobble side to side, it's that perfect of a fit. I put a thin piece of foam, they sold it there to use to cut out shapes and letters, at the bottom of each container just for a little extra padding, but I really wouldn't need it. Here are some pics to help anyone who is interested in finding it, and see how they fit:
The positve spring sticks up just above the top, so with the lid on it puts a little bit of pressure on it which helps to hold it in place. I'm not sure if this would be ideal for some of you, so I thought I'd point this out:
I have a Surefire P60, Dereelight 2-stage Q2 module w/ reflector, a spare Dereelight reflector on the bottom left, here there was a gap between the reflector and the lid so I just put in a piece of pluck out foam in there that I had left over from a case with pluck out foam, or whatever it's called.
I also have the new Fenix red filter in one of the containers, so it fits as well:
It's a nice little case, would be easy to grab and take along, or throw into a larger bag, suitcase, etc. The case securely holds each container when closed, but they shake around a little:
While I found this case at an AC Moore, it's possible they could be in other craft stores, Michaels, Joanne Fabrics, etc. Probably any place that sells beads for making jewlery could possibly carry it.
The label, which I ripped when opening it, says "Bead Caddy" and has a web address,
www.nicolecrafts.com so you could probably order it from them online possibly, I haven't checked.
You can click on any of the images for a hi-res version.
I have one I got there that works great. I bought the USA made on rather than the Chinese one. It was about 40 cents more, but alot better quality which also means I won't have to replace it again in a year. 
