As I basically drowned on Twitter, let's try here to see if someone can help me out: what would be the cheapest possible device that has some kind of location (GPS etc), some kind of display and some kind of input?
Context: I created whenwhere.cf as a proof of concept for hopefully some day creating a cheap device for addressing in the poorest regions, when phones are a luxury. Having cheap navigation and addressing without map or internet dependency can hugely improve people's lives.