From their website:
The Kickbee is a device that updates Twitter when a baby kicks its mother from the womb.
Long commutes and longer workdays force many expecting parents to spend considerable time away from one another. Whether separated by hundreds of miles, or by a simple daily commute, the separation can be heart wrenching for the upcoming parents as they struggle to support one another for this major change in their lives. The Kickbee is intended to help bridge the physical gap between spouses by enabling pregnant mothers to share the experience of a baby kicking in the womb with the fathers...an event that is normally only experienced in close proximity through the touch of the father's hand to her belly.
The Kickbee is a stretchable band worn by a pregnant mother. Vibration sensors are attached directly to the band, and are triggered by movement underneath. The band and electronics are covered in a soft fabric cover for design and comfort. A microcontroller in the garment captures the movement and transmits the signals wirelessly to a computer running a custom application.
The application receives the sensor values and analyzes them. When a kick is detected, a message is posted to the social messaging service Twitter via its API (Application Programming Interface). Twitter makes it easy to share these short messages of "I kicked Mommy!" with family and friends, and allows them to be sent as text messages to any mobile phone in the world. The Twitter account can also act as a data log that can be accessed later for visualization or archiving.