Sun Spot

Sun SPOT (Sun Small Programmable Object Technology) is a wireless sensor network (WSN) mote developed by Sun Microsystems. The device is built upon the IEEE 802.15.4 standard. Unlike other available mote systems, the Sun SPOT is built on the Java 2 Micro Edition Virtual Machine (JVM).
The completely assembled device should be able to fit in the palm of your hand.
180 MHz 32 bit ARM920T core - 512K RAM - 4M Flash
2.4 GHz IEEE 802.15.4 radio with integrated antenna
USB interface
Sensor Board
2G/6G 3-axis accelerometer
Temperature sensor
Light sensor
8 tri-color LEDs
6 analog inputs
2 momentary switches
5 general purpose I/O pins and 4 high current output pins
The motes communicate using the IEEE 802.15.4 standard including the base-station approach to sensor networking. This implementation of 802.15.4 is not ZigBee-compliant.
The device's use of Java device drivers is particularly remarkable as Java is known for its ability to be hardware-independent. Sun SPOT uses a small J2ME which runs directly on the processor without an OS.