Clapper.
Clap on, clap off.
I'm getting ready for vacation and don't have the time to do much modding. I will log in just to see what is going on from time to time. The touch switch idea will be a tough one. Not getting it to work, getting it to work in such a manner than everyone would like it. Too sensitive, not sensitive enough, doesn't work with my old dry fingers but works fine with for the wife. Comes on all by itself when I have it in my pocket and get all sweaty. See, tough to please all. The one point about not allowing operation in the linear zone would not be an issue with PWM. Set an upper pulse width and rate for the type atty you want to use (would be different for LR, Standard, clone, HV attys) and the switching FET is flipping very rapidly from full off to full on. Never pausing in the linear zone. Touch switch combined with PWM would give you pressure sensitive vaping strength, and if set up properly, never too much for your atty. A second touch "Zone" could even be set up as master power. Touch on, touch off. LED for power, LED for vaping power (brighter for more vaping power). Maybe all of this can be made into a FRU (Field Replaceable Unit) in maybe a 3/4 copper pipe cap. You really have to try and out think everyone to come up with something everyone would like. Not simple.
I wouldn't like it if it didn't have an MP3 player also.
Cisco is working on a PWM variable power level MOD. I don't know if it's going to be touch sensitive, pressure variable or not.