This paper presents wearable opportunistic controls using unmodified clothing buttons. Buttons are commonly sewn on formal clothing and often came with multiple duplicates. In this paper, we turn passive buttons into dial widgets. Each button provides simple input modalities (e.g., tap and spin inputs). Multiple buttons allow for modeless and rich interactions. We present AnyButton, a wearable motion-sensor set, allowing for transferring buttons on clothing into mobile input on the move. Our prototype consists of three motion sensors attached on the index fingernail, the wrist, and the elbow. We interpret which button is under user interaction according to the wrist and elbow orientations, and how the button in the user's finger pinches being operated according to the motions on the fingertips. Each button allows for partial tap, discrete spin and dwell spin inputs. By distributing interface to the buttons, applications such as music players and call centers can use opportunistic clothing buttons as wearable controls.