A project to build the $50 phone has been launched on Crowd Supply, promising to deliver "an open-source, Linux-powered" handset with "no carrier locks, bloated apps, or data mining" and that "doesn't depend on big companies".
The ZeroPhone will be based around the tiny Raspberry Pi Zero, an Arduino microcontroller, and the ESP8266 Wi-Fi module.
The ZeroPhone comes with several extras not found on your typical handset, including a mini-HDMI port and a single full-size USB 2.0 port, alongside the more typical support for Wi-Fi and a 3.5mm headphone jack.
One downside is the phone will initially launch only with 2G GSM connectivity, with 3G expected to be added later. The screen is also far smaller than is typically the case, with a 1.3-inch, 128 x 64 OLED display.
To get the most of the phone users will need to be technically proficient. While the splash page for the project says the likes of IR receivers and the Pi's 5 and eight-megapixel cameras can be wired up the phone's electronic interfaces, this will require users to hook up the electronics themselves.
However, if you're confident using the Linux terminal, you'll be able to SSH into the device for remote access and run a wide range of Linux software on the phone.
It can even be hooked up to a keyboard and mouse and used as a desktop, although the Pi Zero's ageing single-core processor isn't capable of running a heavy graphical desktop comfortably.