A useful JME2 app for GPS datum conversion i.e NMEA WGS84 to MGRS, OSBG36, UTM, UTM 1:25000 map, decimal degrees conversion etc. Which allows cellular phone GPS with real paper maps.

http://utmdata.blogspot.com/

Also will compute lots of other useful information such as sun, moon set and rise times, moon phase and the full location data can be sent via SMS text message and load the appropriate Google map tile. (if network services are available)

Looks very useful, but apparently it is only for the somewhat outdated Series 60 phone platform. I didn't see any reference at the link to an Android version.

It runs quite nicely on a newish Samsung B2710 and should work on most non smart phones with J2ME (most celluar handsets) cross platform support. The main idea is the ability to still have a useful navigation tool in conjunction using a paper map when cellular network access is unavailable rather than having to rely on a GPRS connection to download Google map tiles for the GPS overlay. I haven't been able to find an Android or iOS so far that performs the same function. Navigating using just raw WGS84 lat and lon coordinates without a electronic map is possible but would be rather tiresome.

WOW! That made absolutly no sense to me. Is it Russian?

GPS being a US military system produces coordinates that Google maps and Google earth use natively. The coordinates use a World Wide Datum called WGS-84 i.e. World Geodetic System 84.

Most GPS's will output NMEA 0183 sentences on their communications port which also use the same WGS-84 datum.

The world is basically a flat ellipsoid shape and paper maps are flat and the easy to use flat paper maps will use a grid system (Cartesian coordinates) such as the Ordnance Survey Maps in the UK or the Military Grid Reference system MGRS etc

http://www.ordnancesurvey.co.uk/oswebsite/gi/nationalgrid/nationalgrid.pdf

The calculations to turn native GPS output i.e. using the WGS-84 datum into a flat grid reference can be a little difficult by hand.

http://www.movable-type.co.uk/scripts/latlong-convert-coords.html

i.e. The computer program on the cellular phone will convert between the native GPS and the Grid coordinate systems)

Lat (WGS84) N56:40:30 (56.675060)
Lon (WGS84) W3:00:13 (-3.003490)

becomes

OS Grid NO386541 (this is so much easier to locate on a OS 1/25000 and 1/50,000 scale paper map grid)

Distance between OS grid coordinates simply become basic Pythagoras for example.

The paper map you use will have a specific datum (written somewhere on the map). When using a commercial GPS you need to ensure that the GPS also is using the same datum as the paper map and not WGS-84 or you may get some significant navigational errors.

Hope this helps.