The Digispark is an Attiny85 based microcontroller development board similar to the Arduino line, only cheaper, smaller, and a bit less powerful. With a whole host of shields to extend its functionality and 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.
Note: The Digispark is shipped fully assembled except for the two included and easy to solder headers.
Warranty Period: 12 months
Features
Support for the Arduino IDE 1.0+ (OSX/Win/Linux)
Power via USB or External Source - 5V or 7-35VDC (12V or less recommended, automatic selection)
On-board 500ma 5V Regulator
Built-in USB
Plug directly to your laptop or computer USB port (type A)
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)