GPS reads out coordinates lat-long of the WGS84 system Many countries use maps with different coordinatesystem (e.g. in x,y in distance-units rather than degrees - UTM grid, national grids, etc.) Dedicated GPS receivers usually allow to choose a projection... including to set a [CUSTOM...] projection where you fill in a series of parameters... and if you set the paramaters right... it gives the intended coordinates (or approaches them with reasonable precision). [[e.g. http://gpsinformation.org/dale/measure.htm User Grid ]] A utility allowing to display UTM coordinates, including a USER GRID option to further project from there (like build-in in dedicated GPS receivers) -- would be neat. One could think of building in a library of national grids etc. making use of existing ProjectionLibraries (e.g. http://www10.giscafe.com/wwwthreads-5.3/showflat.php?Cat=3&Board=gis_education&Number=121921) - perhaps to be ported to the android dialect.