Although i don't have a Touchscreen yet, i did start thinking about how the control should look like. Started with a button. I've come up with this, a toggle button working similar to what i'm using on the Pronto:

Now the question for the touch-experienced users is: shouldn't it be better to put the green indicator bar above the text, so your finger won't hide large part of it? Cause all i see in other threads is indicators at the bottom. Why? Because it's prettier? Other considerations?