Portrait mode. With PR 1.0, only the phone application, and the photo viewer officially supported it. With PR1.1, the browser has the ability to switch to portrait mode, but seems to be a work in progress. Do you see ubiquitous portrait mode in the future of the N900 for all official applications, or is this something that will be treated on a case-by case basis? For some of us that evolved from tablets, portrait mode in all applications may feel unnatural, whereas the opposite is true for those Maemo-newcomers who have gravitated here from other phone platforms.
PS: Nokia N900 was designed with focus on use as mobile computer with the telephony as a feature. Hence, the wide support of landscape orientation. Based on consumer feedback, we are adding portrait support in the browser of the Nokia N900, but only our MeeGo 1 software (formerly known as Maemo 6) will have full support of portrait and landscape orientations of all applications.

Source: http://mobiletablets.blogspot.com/20...ith-peter.html