You can do many things with the Raspberry Pi mini-computer, from brewing your own beer to playing Quake.
And now you can make calls with it, too, thanks to David Hunt's PiPhone. The intrepid engineer has packed an Adafruit PiTFT touchscreen, 2500mAh battery and SIM900 GSM card onto a Raspberry Pi to create a working phone.
Yes, its feature set is a bit limited – it can send and receive calls, and, er, that's it – but as a proof of concept it does the job nicely.
here are just one or two problems standing between the PiPhone and world domination. Firstly, it runs very hot, as there's little room for air circulation. Secondly, the cost of all those components comes to around £95 – which, given that you can pick up a full-featured OnePlus One smartphone for £230 – is a bit steep.
Still, if you fancy making your own PiPhone, Hunt is planning to upload the code for his software to GitHub. Good luck!