The ESP8266 is a cheap WiFi SoC. It should allow us to make gateway nodes which do not require a PC to upload to the internet.
Out of the box the module can be controlled via AT commands at 57600 baud serial. I found controlling it using an AVR to be a bit sketchy at this speed, but worked better at 9600 baud after updating the SoC firmware. It runs at 3.3v and needs a reasonable supply (240mA peak during tx, 70mA idle).
As of writing it seems only WEP encryption is supported. With any luck this will soon change with a firmware update as the hardware supposedly supports it. I have flashed my chip with V0.9.2.2 from electrodragon and WPA2/PSK seems to be working. :D
The chip has a whole bunch of quite nice features, including SPI, meaning that in theory you should be able to eliminate the micro from the equation. ESP-03 with more GPIO's ordered, need to do some digging to figure out how the SPI works.
I'm using a 8MHz crystal and an LM2937-3.3 SOT-223 3.3v regulator.
I put together a library for sending HTTP POST requests to the ukhasnet server from an ESP8266 via AT commands. The ESP8266 Library, repeater/gateway code (credit to Phil) and PCB files are up at https://github.com/chrisstubbs93/ESP8266