A while ago I found a board for sale that is about the size of a Raspberry Pi. It comes equipped with an Atheros chip for Wi-Fi communication, in addition to possessing some capability of executing programs. It is basically the board inside of those mini routers, except intended for use in projects rather than for use as a router. I ordered one about a year ago that I have lying around and will use. Unfortunately the name of it is escaping me at the moment, but it has a pcb that is some shade of yellow whose name I am uncertain of.