MAKE magazine has featured on their blog a device that does everything I wish I had thought of to do when my wife was pregnant. The device sends all manner of updates to Twitter (which you can follow here).
Gizmodo summarized the function neatly:
Piezo sensors detect the baby’s movement and transmit electrical charges to an Arduino Mini microcontroller, which in turn transmits the data to a Java application via Bluetooth. This Java app deciphers the meaning of the signals, and posts on Twitter when it determines the baby has kicked.
Clever use of technology and Twitter, and more useful than a blogging plant.