ok... maybe another idea works...
since most of the iphones and many other devices have a internet flat rate...
would be a Wherigo-web-application a option?
making a webapplication for many mobile devices is maybe easier then making a complete app for a single device?
the only problem is... how can the webserver get the position of the device through the webpage...
but if it is too difficult... i will wait until the "official" iphone app is ready...
i think if you tell ppl about it in some blogs and ask how fast they want it.. there will be a huge feedback.. ;-)