I'm in the planning phases of a mobile-based game that depends heavily on tracking your location (think FourSquare). The main problem I have is storing and tracing location.
If a user has a phone with a data plan, I can simply ask them to turn it on at the target location to allow me to save that information (that they visited location X). But what about if they don't have a data plan?
FourSquare allows you to use some sort of SMS system to "check in" to locations, but implementing that is beyond me. What I probably need is some way to just figure out and temporarily store the user's location, and when they next connect online, they can upload all the "visited locations" information.
I know this is vague; I'm looking for general solutions. If you want specifics, I will be using MonoGame and supporting iPhone and Android phones.