by Matt Richardson @ makezine.com:
Spark has improved and expanded their product line with the Photon wi-fi development board and a pair of new wireless modules for custom circuit boards. The Photon improves on the popular Spark Core microcontroller by adding 802.11n wi-fi connectivity, SoftAP for provisioning, more memory, and a faster ARM Cortex M3 processor. Like the Core, it sits right into a standard breadboard for easy prototyping. And best of all, it can be had for $19.
Photon – A Wi-fi Microcontroller for $19 – [Link]