last resort that are too shy to ask the nice guys and gals of LARS etc
Ah! - maybe what's called for is a ride with an instructor doing some radio practice then.
If you've managed to completely lose yourself such that you can't find out where you are using
- map
- VOR
- ADF
- DME (OK, so personally I've never tried to fix my position using nothing but DME and a chart and a pen, but it's obviously possible)
and there's no GPS built into the aircraft, then provided your radio is working you've got
- VDF [#]
- LARS
- a call to London Centre on 121.5
all of which will tell you something useful about where you are, and all of which are best practised when you aren't actually lost, so that you're confident doing them.
If that's not an option, eg because you've got a total electical failure, then sure, any hand-held widget, even one as inappropriate as a mobile phone running car navigation software, could turn out to be better than nothing.
But I would claim that this is a
last resort, to be tried
after all attempts via radio to get someone on the ground to help you have failed.
Plus, if you're lost, there's a fair chance you're in someone else's airspace, and I can assure you that they would much
much rather you called them first rather than spent time fiddling around with some electronic toy.
[#] I made a practice QDM call once. I got the expected response, but didn't follow the given course, because I wasn't planning on returning direct to the field. I got called up a few minutes later by the controller giving me a new QDM - clearly he was assuming that I was (a) lost and (b) having problems following the first QDM he gave me. Perhaps I should have said on the first call that I wasn't lost and just wanted to see what a QDM call was like in real life.