So you would like to have additional fingers to carry objects and get more done with your hands? The Third Thumb project is a wearable solution that lets you do just that. Dani Clode is the maker behind this project. The Third Thumb is a motorized finger that you can control with your feet.
The wearable system consists of a flexible thumb, two servos, batteries, and Bluetooth. The above video shows what you can do with it. More info is available here.