I recently learnt this trick - and apparently it falls into one of those gems on my smartphone that has been around a while, just I didn't know about it!
The crux of the trick is to type into the Google Maps App search bar 'ok maps' and it will save/cache the mapping data for you to access later offline. The beauty of our smartphones/Google Maps is that you don't need mobile data for the 'blue dot' of the GPS to tell you where you are. Obviously it has some limitation to zooming in and load more micro data and rendering of the map, but in a couple of test runs I tried, it worked just fine.
This has certainly one-upped my old method of taking screenshots (which used to work OK), but were clumsy to refer back to and never showed your new location dot. I am also aware of a few Apps that use OpenStreetMaps to cache mapping data in a similar way, but have never used them.
If you know of one or two good offline maps Apps or a better way to store mapping data on your phone, please note them in the comments for everyone!
Written by Peter Cain
Peter Cain is the Founder and CEO of dataGO.co, a company committed to making it easier and cheaper to stay connected whilst travelling. You can find him on Twitter and Google+. You can also find dataGO on Facebook, Twitter, LinkedIn, and Google+ for all the latest info on local and roaming SIMs and data hotspots.