[bch]

> They don't provide knobs because they're a bad idea for input

I like knobs because the distance from the center of that control (radius of your arc movement) can be a “fineness” or “coarseness” control. I think sliders don’t usually offer this.

[rickbutton]

Some iPhone apps provide this for the time slider (I believe via the native media player control, although I could be wrong). It is very nice.

[bch]

I’ve seen this too, and yes, it’s nice. I don’t know where in the stack this feature lives.