Disappearing home buttons/onscreen buttons?

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Hey Android Army,

So after watching a hands-on YouTube video of the Huawei Ascend D2, I got a glimpse of something that I thought was a great feature to the phone. As you may or may not know, the Ascend D2 has a 5 inch 1080p display and quite naturally, you would want to see the entire display in all its glory.

The way the on-screen buttons worked on the D2 was that you had a small downward pointing arrow on the far left of the on-screen buttons, once you tapped them, they swiftly slid down off of the screen to reveal the whole real estate of the display. And to bring the buttons back up? You just slide up from the bottom of the screen for them to pop up again.
Not only can this just be used on the home screen, but also in applications and whilst browsing the web.

The next thought I had was that it would be really cool if the Google Nexus devices had this smart feature also. I personally think the Google Nexus 4 design would compliment this feature very well.

Who knows? Maybe this is something that may be in the next Jelly Bean update or something that would be considered.

But who else thinks this is a great touch to have? And if so, would you like to see this implemented on other phones too?