Don't you have to own a Mac to write apps for the iphone? A friend of mine is a software engineer in London and he bought one just so he could start writing them. I reckon there are more people writing more apps for Android as it is open source - even I have the Android SDK on my laptop here and was going to make a few flight planning apps just for my own use really - W&B mainly.
Anyway, thanks for the info, when I get back to the UK I'll certainly download the app for my HTC Hero....looking forward to to..
Cheers