ATTiny85 Module - Digispark with Micro USB

The Digispark is an Attiny85 based microcontroller development board similar to the Arduino line, smaller, and a bit less powerful. With the ability to use the familiar Arduino IDE the Digispark is a great way to jump into electronics, or perfect for when an Arduino is too big or too much.

Here are the specs:

Support for the Arduino IDE 1.0+ (OSX/Win/Linux)
Power via USB or External Source - 5v or 7-35v (12v or less recommended, automatic selection)
On-board 500ma 5V Regulator
Built-in USB
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