$13 Arduino Boards now at Evil Mad Scientist Labs
Evil Mad Scientist has just released Diavolino, a low cost option for those who like to do arduino development, take a look:
"Diavolino ("little devil") is a low-cost, easy to build Arduino-compatible development board.You can buy them here
Diavolino has the form factor of an Arduino Duemilanove or Arduino Pro, but with nicely rounded corners and a striking appearance. It's a low-profile through-hole version, with a simplified design.
It's based on a ATmega328P microcontroller, and comes pre-flashed with the Arduino bootloader. Open source design, with bare basics hardware."