I recently tried out two tracking apps for Android, MyTracks aced GPS Tracker.

My Tracks is produced by Google themselves. It will track your location, give various speed and altitude readings if you want, and doesn't need a mobile connection to work. BUT, the data is only stored on your phone, you have to upload it manually to Google, for anyone else to see, although once it's there you can do all sorts of fancy things including Google Earth flyovers.

GPS Tracker is an independently produced app which ties in with Instamapper. You'll need an account with them, but it is free. GPS Tracker will give you almost no useable data on your phone. BUT what it will do if you have a cellphone signal is upload your position in real-time to the Instamapper servers, which can then be used to give your location on a map either accessed through their website, or easily embedded on your own.

Both of them have surprisingly accurate tracks on a recent day's off-roading round the Chilterns tying in very nicely with the tracks from a dedicated Garmin unit. You find strange wanderings when the phone is still, this us down to it using GSM signals to triangulate, but when it's moving they seem to stabilise being accurate down to a couple of metres.

So it's really a question of what you want. Do you want something you can replay, export to various computer programs and back into a GPS device, but which doesn't need constant GSM coverage? Or do you want to leave a breadcrumb trail for your friends and family back home and are travelling in an area where mobile phones are common?

The good news: they will both run simultaneously, and in conjunction with a sat-nav app, so you can have your cake and eat it.

The bad news: you will have to accept the limitations that come with smartphone use. Poor battery life, possible fragility, lack of rugged mounting solutions. But smartphones will only get better, smarter and hopefully less power hungry, and in the mean time, you can always wire in a 12v socket.

__________________