I noticed a bug report about portrait mode on the Nokia N900′s web browser. Wait… there’s portrait view now? It seems this hidden feature can be enabled on the web browser by pressing Ctrl-Shift-o. This works on the latest Nokia N900 firmware 2.2009.51-1 and seems to be an undocumented feature. I made a video to show you how it looks.
Pressing the three buttons toggle it on and off, maintaining the setting even after rebooting the Nokia N900. The screen automatically rotates when the keyboard is closed and the device is held upright. It goes back to landscape view if keyboard is slid open. The on-screen keyboard also appears in landscape view only.
Despite some of the drawbacks I mentioned above, it’s cool that Nokia left this “hidden feature” to be found by its users. I believe this option was hidden because it is simply not finished yet.