The ESP-8266 packs a lot of networking power into a small package. Some would say too small, which is why they often come on a slightly larger carrier PCB. The PCB is usually little more than a breakout with an optional 3.3V regulator. [Frazer Barnes] went one step further: he put an equally tiny USB to serial bridge, an oscillator, and some power management on an ESP-8266 breakout board.
You can program the ESP-8266 via the serial port, so having a built-in USB port is handy. Of course, you might not need it in the final product, but with the board being 25x30mm, you can probably cram it into most projects. [Frazer] posted a bit about the project on Hackaday.io, and has a GitHub project, although right now the upload of the design files is pending.
There’s no shortage of ESP-8266 projects. We saw a small Zigbee to ESP8266 board last year, and also the antidote for a tiny carrier board that includes an LCD, switches, and more. We also have tons of breakouts on Hackaday.io: here’s one with all the bells and whistles, and a similar, stripped-down version. All open-everything, and ready to go.