[mappum]

You can get them for $4.70 with free shipping directly from the factories in China on Aliexpress: http://www.aliexpress.com/item/New-Wireless-module-NodeMcu-L... (The only downside is shipping takes a few weeks).

Just received 2 of them a few days ago, and they work great! I had been waiting for practical IoT hardware for a long time, and now it's finally happening.

I recommend ESplorer for programming them (http://esp8266.ru/esplorer/), and esptool for flashing firmware (https://github.com/themadinventor/esptool).

[StavrosK]

Thank you for the recommendation, I ordered three. The tools are going to be very handy, as I don't like the Arduino environment very much.