"SUI cube" progress video #1.
I have used a QT110 touch sensing chip, connected to conductive thread sewn in the top of a button, to sense when my finger is touching the top of the button before I press the button. For now, the button touch and button press are with separate buttons, but functionality will be combined eventually. All components are controlled with an Arduino.
See http://www.stackedui.com for more details.