SPECIFICATIONS:

1. Support for the Arduino IDE 1.0+ (OSX/Win/Linux)
2. Power via USB or External Source - 5v or 7-35v (automatic selection)
3. On-board 500ma 5V Regulator
4. Built-in USB
5. 6 I/O Pins (2 are used for USB only if your program actively communicates over USB, otherwise you can use all 6 even if you are programming via USB)
6. 8k Flash Memory (about 6k after bootloader)
7. I2C and SPI (vis USI)
8. PWM on 3 pins (more possible with Software PWM)
9. ADC on 4 pins
10. Power LED and Test/Status LED

 PHYSICAL DIAGRAM: