This is a three axis accelerometer for the LilyPad system. Based on the ADXL335 accelerometer from Analog Devices, the LilyPad Accelerometer can detect joint movement as well as inclination and vibration.
If you're looking for a simple way to add a battery to your LilyPad project, the LilyPad Coin Cell Battery Holder might do the trick.
This is the LilyPad Arduino Simple Board. It's controlled by an ATmega328 with the Arduino bootloader. It has fewer pins than the LilyPad Arduino Main Board, a built in power supply socket, and an on/off switch.
Magnets. How do they work? We're going to guess magic. This particular set of magnets are pretty darn strong, are able to rotate freely, and conduct electricity. That's a pretty darn good kind of magic, if you ask me.