The 16F72x parts have some "built in" touch sensor functions.
I've used them. Most of the relevant data sheets, and some of my "early progress" with touch sensors can be found here:
http://www.picbasic.co.uk/forum/show...ght=capacitive

They work pretty well. The real trick is doing appropriate averaging to kill any noise spikes from triggering the touch sensors. One of my "early version" temperature controllers will increment it's set temperature a couple of degrees every time I turn OFF a particular fluorescent lamp in the same room.
I've been too lazy to open it and fix it....


steve