Judy Breck asks, over on Smart Mobs, if it's about time for a mobile phone with a dual screen? The thought is inspired by the new Lenovo laptop that has an extension to the regular screen in the lid that slides out to the side, providing an almost Cinerama experience. I suspect that my reaction would be similar to any Symbian OS follower, namely a discrete cough before pointing out the Nokia Communicators.

I think Breck is actually aiming for a little more than the much-loved clamshell communicators that had a regular styled screen on the outside to allow the devices to be useful when closed, but to have a larger working area when using the device, that then collapses down to something that's easy to carry.

Smartphones, for all the bells and whistles, are compromise devices. You have to give up a lot for the portability and convenience they offer, and in the main that means the screen size is going to be either very small (the N85), have a very high pixel density (the iPhone and iPod Touch), or increase the size of the device (the E90); and the input mechanism will also not be the Qwerty keyboard you get on your desk, it will either be much smaller (the E63 and E71), or replaced by a touch screen (Nokia 5800) or ABC number pad.

There is no right answer here on how to make a bigger screen in a device, it is going to come down to personal preferences. What manufacturers need to consider is that people's phones are going to be used in a variety of circumstances that need certain types of a/v outputs. The obvious enterprise case here is to make presentations, and Bluetooth is starting to become more available in projectors. Nokia also have the option to run TV-Out from a number of their S60 phones.

As long as the manufacturers continue to build a diverse portfolio, and provide routes to get the media out of our phones to other screens and speakers, I think the current crop of phones will do nicely without sliding out screens or flexible OLED displays.

-- Ewan Spence, Jan 2009.