One way to implement portrait mode via automatic screen rotation (ASR).
Have the phone rotate it and if it is too big to fit, then you have to scroll around (kinetic scrolling comes in useful here?). This will at least have the mode until there are "proper" portrait mode UIs. Those who don't want to make a UI can leave it if they want, their choice.

ASR should also be switchable on or off, and perhaps with an option for permanent portrait or permanent landscape (the default).

An example of this could perhaps be (simplistically):

on event change accelerometer_value
if accelerometer_flag= "OFF"
end if
elseif <program>_allows_ASR = "OFF"
end if
else if accelerometer_value = "Portrait"
then call <program>_UI_portrait
else call <program>_UI_landscape
end if

Ok this is very basic and I should get back to SQL statements... it's been years since I programmed in C++, this looks more like VB...!