Teensy USB Development Board
The Teensy is a complete USB-based microcontroller development system, in a very small footprint, capable of implementing many types of projects. All programming is done via the USB port. No special programmer is needed, only a standard "Mini-B" USB cable and a PC or Macintosh with a USB port. Update: Discussion / Support Forum Teensy 3.1 changes from Teensy 3.0 Teensy Loader Application Software Development Tools WinAVR C compiler. Teensyduino, add-on for Arduino IDE. Simplified USB Examples or Dean Camera's LUFA library. Breadboard Usage The Teensy is available with header pins, for direct no-soldering-required use on a breadboard, which can also be run from the +5 volt from the USB cable. The 128x64 Graphics LCD can be used with Teensy 2.0 and Teensy++ 2.0 and Teensyduino using this GLCD library.
Related: Small Arduino boards