1. For folks who are not in the USA we tendnot to use NAD co-ordinates on our GPS - is there much conversion/tweaking of your conversion routines to allow for this in the route files [e.g. for those of us who use WGS84]?

Once you're in 'empeg space', everything is WGS84. Only the python script that massages the route does datum conversion.

It is trivial to add any other datum, you just need to add the right values of 'a, inv, dx, dy, dz' corresponding to that datum. Typically a google search or a quick look at programs like gpsman and gpstrans will turn up the ones you need. And it shouldn't be too hard to understand how to add it to convert.py (look for Ellipse_Clarke1866 which is where the datums are defined).

However, as far as I know, mapsonus can only route in the US, and somewhere in their site it said that all coordinates are in the NAD27 datum. So for that particular conversion it isn't necessary.

Am I correct here in this behaviour - it would look to be consistent with how other apps like Empacman work?

Yes, pressing the top button 'exits', however this isn't a real application exit, so all the state will still be there. i.e. we still has the same route loaded and preferences set and will immediately try to find our new location in the route when we 'start' the application again.

I don't think I can 'hijack' the display when I haven't officially returned from the WAITMENU ioctl. I did figure out that setting an alarm provides a nice way to get unstuck from the WAITMENU ioctl, so I could have the app do something even when it isn't visibly running (popups/beeps/voiceprompts?). I can re-add that code in 5 seconds flat if you think it would be useful.