I'm sitting here admiring my iPhone 4, and thinking of how far it's come since the original iPhone. One thing that catches my attention is the glass back. Love it or hate it, it expands new possibilities. What if the a future iPhone had a touch sensitive rear that can be used to scroll? That way you can continue to view the entire screen without your thumb or finger blocking your view. Apple tends to open new doors rather than play catch up with useless features that other phones have. Thoughts?