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 had some boards made by Hackvana with an RFM69HW, ATMega328P and various headers including one for the ESP8266.
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
You will probably need to flash the V0.9.2.2 firmware from electrodragon (upload instructions there) for this to work, as the AT command responses are slightly different.
GitHub wiki with compiler info etc: https://github.com/esp8266/esp8266-wiki/wiki
Other info: https://nurdspace.nl/ESP8266
Post on my blog about the board: http://chris-stubbs.co.uk/wp/?p=563