Android Question Multi touch button or "Slide switch"

I'd like to make a button that can't be activated by a simple accidental touch so either a multitouch that needs two fingers to touch specific areas at the same time or a "slide switch" (needs to be fairly large, I.E. Finger sized so it's not fiddly to operate) It also needs to change colour and text label needs to change depending on state (could do that with two different images?) I did the two finger multitouch thing AGES ago but can't for the life of me remember what view etc. I used other than the "Gestures" library was involved and I used two images to show the state. Any pointers on where to start looking?

Martin.