there are adapters out there, however MV doesn't sell one ready-made. You can get a 901
battery extension though, then just cut a tiny hole in the side with a dremel tool. I tried drilling a hole first, but the tubes seem to be made of steal and are incredibly hard to drill without a high-speed rotary tool. I finally took a needle file and used it like a hacksaw to cut a slit into the side. Ugly? Yes. Functional? Yes.
Also, before I got the extension, I just used a tiny drill bit (1/32" or 1/64") to drill a hole on the cartomizer itself going diagonally from the bottom corner of the battery connector to the outside of the carto. This worked wonderfully as well. It allows you to use a carto directly on a 901 battery, giving you an almost perfect 100mm length. It fits in a pack of analogs no problem.