Skinput is a technology that uses the human body as an input surface by sensing vibrations on the skin caused by taps and gestures. An array of vibration sensors can detect finger taps on different locations on the arms and hands with over 80% accuracy on average. Tests showed higher accuracy for taps below the elbow compared to above. Identification was slightly reduced for participants with higher BMI. Further experiments explored uses while walking/jogging and recognizing single-handed gestures, surfaces, finger tap types, and segmented finger input. Skinput provides an alternative to small device screens for mobile interaction.