I was thinking that a cheap wireless doorbell would work quite well as a zero-config, reliable, long life wireless button input…
But the wireless doorbell I’ve got hold of doesn’t have an LED on the speaker unit I could easily use as an input to interface with the photon - I’m presuming it’s not necessarily safe to just identify a wire which goes HIGH on the speaker unit and connect that through a resistor to the Photon? Or is it?
Alternatively, get yourself a cheap 433MHz transceiver and listen to the button press directly.
That also highlight the main issue with a setup like that. Others around you could be broadcasting the same code, thus trigger your button. That may be on accident if they happen to have a similar transmitter, or on purpose. The RFXCOM for example is a popular hobbyist solution for sending/receiving, and with that duplicating, wireless signals like these. If you have someone in your neighborhood that’s feeling funny, they could mess with that button.