Hi Harold, no I haven't - it looks really interesting - especially a solar powered one. I'll look into the site in more detail - I don't think I've 100% got my head around all the different information regarding US wireless spectrum at the moment - but you could see how it could be used elsewhere too.

I did have another thought actually re self-authoring - at the moment due to screen size it would be quite difficult to do - but I think there are some ways to display the code on the phone's screen eg http://www.mobpartner.com/tools/source/

And/or use a mobile projector (don't know pricing yet) then providing you have somewhere you can project it onto, you could also collaborate with others to help you write the code.

If you did not have others around to help physically and you were having difficulties making code work - or just wanted someone to check it, you could maybe use some kind of SMS messaging to text your code to a website where others can reply and you receive that back via text.(e.g. if you were based somewhere in Africa, maybe use a website like AfricaNews community forums or someone like that who already have good understand of mobile issues within somewhere like Africa).

So, once you have your application and assuming you have been able to successfully test it, I guess then find the way of releasing your application. Maybe using a loan system like Grameen banking to start off but that may not be possible so find a model like one of the 3 you mention above ?