Slightly related to the topic perhaps, because with an ssh daemon as well, you could log in to your device and initiate tracking or whatever you liked to do (warning notifications and whatnot). You could then do it when you needed to, instead of doing it all the time/regularly.
I think miniGPSD has this function already. Also, at least Fennec will have geolocation APIs, so you could try and rip that out of their code.