The body is a flashlight shell from Dealextreme - an MDXL. I fabricated the connector from a tire valve, a brass screw cut and polished for the positive connector, and a nylon spacer (that I had to sand down a little to fit inside the valve stem. For the switch, I used a micro-momentary tactile switch. I used the switches that have a 9.5mm tall button so I could shave it down to the length need - I test fitted it in the flashlight house and dremeled it down to size. In case someone is interested in making one of these, keep this in mind: 1- You have to use a micro switch; anything bigger will not fit because it is sharing space with the atomizer. 2 - For the same reason, only a 901 atomizer (or thinner) will work for this mod. 801 atomizers are too thick. 3 - since the hole of the 901 atomizer is inside of the flashlight, you may want to drill another "breathing" hole in the shell.
Since I am using protected CR123 cells, I had to remove the spring and cut it down a little - the lack of room prevented me from installing the switch at the bottom of the shell. Since the actual atomizer sits inside of the shell (and the switch can be seen), I finished off the top of the shell with a black nylon hole plug; drilled out a center hole that the atomizer could fit through.