Split Screen on Full Screen Mobile Devices

Let me just put this out there.  Would you want the ability to have a split screen on your full screen mobile device?  You'd ask:  What for?

Let's take the iPhone.  With it's 3.5" screen, I love the real estate I'm given for reading, browsing, or viewing video.  With a split screen, I can have two activities going on at the same time.  This is what I want and I like to hear from mobile warriors if this is feasible and just productive one can really be:

• The ability to split the screen so two concurrent activities can take place.  For example, video on the top and browsing on the bottom.  Or for that matter, two browser windows opened at the same time.  
• The split screen sizes can be adjusted to increase or reduce manually giving one screen more space than the other.
• If the virtual keyboard is needed, one of the two activities is automatically paused to provide room for the keyboard and the text box.  Once the keyboard is not needed, the screen goes back to the being split and the paused activity or app resumes.

Sometimes, I love to be able to do two things at the same time.  It's what I mostly do on my Powerbook.  I may be have a video running in the background or off the side while I'm working on Numbers or simply browsing the web.

It's more doable than you might think.  There are not full screen smartphones out there now.  Most smartphones out there like Blackberries and Treos have screen about half the size of what full screen smart phones are and they often used to watch videos.

The full screen mobile devices has the advantage of affording a virtual space not occupied by a physical keyboard.  So, why not offer this feature to users?

In addition, future mobile platforms will like offer screen sizes bigger than the current 3-3.5" screen size. The feature I just described here will not only become more feasible on a device with a 5" to 8" mobile device but, in my opinion, ultimately necessarily.