Attiny85 micro mini USB interface development board, Digispark kicksta expansion board

The Specs:

• Support for the Arduino IDE 1.0+ (OSX/Win/Linux)
• Power via USB or External Source - 5v or 7-35v (automatic selection)
• On-board 500ma 5V Regulator
• Built-in USB (and serial debugging)
• 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)
• 8k Flash Memory (about 6k after bootloader)
• I2C and SPI (vis USI)
• PWM on 3 pins (more possible with Software PWM)
• ADC on 4 pins
• Power LED and Test/Status LED (on Pin0)