Thanks everyone for all the positive feedback... very much appreciated

Here's a shot of inside the battery box...
I've used Raidy's touch switch circuit. But I placed one terminal on the lighter and wired up the steel atty tube as the other. I used the - plate from the base of an AA battery for the touch zone on the lighter.
The steel atty tube is only about 20mm long - all the rest is empty heat shrink tubing (except for the tiny wired LED). I found some great brown stuff in a local store, which has the look an feel of a cheroot when shrunk down - especially with a bit of scorching. It'd be fun to do some in other colours too.
The space at the top of the box (in the photo) could be used for a second battery, but I like to store the 'ciggy' in there when carrying the device around. It's quite neat having everything stored within the body of the compact lighter.