I was thinking more along the lines of having seen the 2 rows by 3 columns = 6 windows on the desktop running dynamically, we can just have those windows rotated into portrait (90 degrees) in the same locations, so we end up with a 3 rows and 2 columns. There may be less spacing between the columns, or the windows will have to be a little smaller, but it should be do-able.

I didn't phrase it correctly, the developer should have the option to lock-in the orientation, be it because they can't be bothered to make portrait, or feel the work is way too much, or that the application makes no sense in portrait, say for example, watching a widescreen movie. You'd really want to watch it in landscape.

Also, I think that an application would probably need a UI design for landscape and one for portrait, and the accelerometer triggers which one is displayed. Yes, it's more work, but I can't think of any other way, so it's up to a developer to decide what to do.

Well portrait mode would have less functionality. Anyone who wants full functionality of widgets can go to landscape mode. It works well on the Blackberry (and mine is fixed as it's not touchscreen, and it makes no sense rotating the phone). I don't really have much experience of the iPhone, but I think I've heard the home screen is only available in portrait mode? I think the menus within Symbian can rotate to landscape or portrait on my N82 (I have autorotation off the screen is off-centre in landscape, though mobitubia is fine in it), but the homescreen is the only one permanently in portrait (excluding developr apps).